IBS Irritable Bowel Syndrome
Irritable bowel syndrome (IBS, or spastic colon) is a symptom-based
diagnosis characterized by chronic abdominal pain, discomfort, bloating,
and alteration of bowel habits. As a functional bowel disorder, IBS has no known
organic cause. Diarrhea or constipation may predominate, or they may alternate
(classified as IBS-D, IBS-C or IBS-A, respectively).
Historically a diagnosis of exclusion, a diagnosis of IBS can now be made on the
basis of symptoms alone, in the absence of alarm features such as age of onset
greater than 50 years, weight loss, gross hematochezia, systemic signs of
infection or colitis, or family history of inflammatory bowel
disease. Onset of IBS is more likely to occur after an infection
(post-infectious, IBS-PI), a stressful life event, or onset of
maturity.
Although
there is no cure for IBS, there are treatments that attempt to relieve symptoms,
including dietary adjustments, medication and psychological interventions,
patient education and a good doctor patient relationship are also
important.
Several
conditions may present as IBS, including coeliac disease, fructose
malabsorption, mild infections, parasitic infections like giardiasis,
several inflammatory bowel diseases, bile acid malabsorption functional
chronic constipation, small intestinal bacterial overgrowth, and chronic
functional abdominal pain. In IBS, routine clinical tests yield no
abnormalities, although the bowels may be more sensitive to certain stimuli,
such as balloon insufflation testing. The exact cause of IBS is unknown. The
most common theory is that IBS is a disorder of the interaction between the
brain and the gastrointestinal tract, although there may also be abnormalities
in the gut flora or the immune system.
IBS has no
direct effect on life expectancy. It is, however, a source of chronic pain,
fatigue, and other symptoms and contributes to work absenteeism. The high
prevalence of IBS and significant effects on quality of life make IBS a disease
with a high social cost.It has also been suggested that a proportion of IBS
patients may develop depression and are thus more likely to commit suicide.
Proposed factors for increased suicide rate in IBS patients include perceived
hopelessness and poor quality of services.
Classification
IBS can be classified as either
diarrhea -predominant (IBS-D), constipation -predominant (IBS-C), or with
alternating stool pattern (IBS-A or pain-predominant). In some individuals, IBS
may have an acute onset and develop after an infectious illness characterized by
two or more of the following: fever, vomiting, diarrhea, or positive stool
culture, This post-infective syndrome has consequently been termed
"post-infectious IBS" (IBS-PI).
Signs
and symptoms
The primary symptoms of IBS are
abdominal pain or discomfort in association with frequent diarrhea or
constipation and a change in bowel habits. There may also be urgency for bowel
movements, a feeling of incomplete evacuation (tenesmus), bloating, or abdominal
distension. In some cases, the symptoms are relieved by bowel movements. People
with IBS, more commonly than others, have gastroesophageal reflux, symptoms
relating to the genitourinary system, chronic fatgue syndrome, fibromyalgia,
headache, backache and psychiatric symptoms such as depression and anxiety. Some
studies indicate that up to 60% of persons with IBS also have a psychological
disorder, typically anxiety or depression.
Causes
The cause of IBS is unknown;
several hypotheses have been proposed. The risk of developing IBS increases
sixfold after acute gastrointestinal infection. Postinfection, further risk
factors are young age, prolonged fever, anxiety, and depression. Publications
suggesting the role of brain-gut "axis" appeared in the 1990s, such as the study
"Brain-gut response to stress and cholinergic stimulation in IBS" published in
the Journal of Clinical Gastroenterology in 1993. A 1997 study published
in Gut magazine suggested that IBS was associated with a "derailing of
the brain-gut axis." Psychological factors may be important in the etiology of
IBS.
Active
infections
There is
research to support IBS being caused by an as-yet undiscovered active infection.
Studies have shown that the nonabsorbed antibiotic rifaximin can provide
sustained relief for some IBS patients.While some researchers see this as
evidence that IBS is related to an undiscovered agent, others believe IBS
patients suffer from overgrowth of intestinal flora and the antibiotics are
effective in reducing the overgrowth (known as "small intestinal bacterial
overgrowthsmall"). A 2012 study, which connected cultures of bacteria
from the small intestine to a significantly increased occurrence of IBS,
supports this hypothesis.
Other researchers have focused on
an unrecognized protozoal infection as a cause of IBS as certain protozoal
infections occur more frequently in IBS patients. Two of the protozoa
investigated have a high prevalence in industrialized countries and infect the
bowel, but little is known about them as they are recently emerged
pathogens.
blastocysis is a
single-cell organism that has been reported to produce symptoms of abdominal
pain, constipation and diarrhea in patients though these reports are contested
by some physicians. Studies from research hospitals have identified high
blastocystis infection rates in IBS patients, with 38% being reported from
London School of Hygiene & Tropical Medicine, 47% reported from the
Department of Gastroenterology at Aga Khan University in Pakistan and 18.1%
reported from the Institute of Diseases and Public Health at University of
Ancona in Italy. Reports from all three groups indicate a blastocystis
prevalence of approximately 7% in non-IBS patients. Researchers have noted that
clinical diagnostics fail to identify infection, and Blastocystis may not
respond to treatment with common antiprotozoals.
Dientamoeba Fragilis is a
single-cell organism that produces abdominal pain and diarrhea. Studies have
reported a high incidence of infection in developed countries, and symptoms of
patients resolve following antibiotic treatment. A 2002 study reported on a
large group of patients with IBS-like symptoms who were found to be infected
with Dientamoeba fragilis and experienced resolution of symptoms
following treatment. Researchers have noted that methods used clinically may
fail to detect some Dientamoeba fragilis infections. It is also found in
people without IBS
Diagnosis
There is no specific laboratory
or imaging test that can be performed to diagnose irritable bowel syndrome.
Diagnosis of IBS involves excluding conditions that produce IBS-like symptoms
and then following a procedure to categorize the patient's symptoms. Ruling out
parasitic infections, lactose intolerance, small intestinal bacterial
overgrowth, and celiac disease is recommended for all patients before a
diagnosis of irritable bowel syndrome is made. In patients over 50 years old, it
is recommended that they undergo a screening colonoscopy.
Differential
diagnosis
Colon cancer, inflammatory
bowel disease, thyroid disorders, and giardiasis can all feature abnormal
defecation and abdominal pain. Less common causes of this symptom profile are
carcinoid syndrome, microscopic colitis, bacterial overgrowth, and eosinophilic
gastroenteritis: IBS is, however, such a common presentation, and testing for
these conditions would yield such low numbers of positive results, that it is
considered difficult to justify the expense. Because there are many causes of
diarrhea that give IBS-like symptoms, the American Gastroenterological
Association published a set of guidelines for tests to be performed to rule out
other causes for these symptoms. These include gastrointestinal infections,
lactose intolerance, and coeliac disease. Research has suggested that these
guidelines are not always followed. Once other causes have been excluded, the
diagnosis of IBS is performed using a diagnostic algorithm. Well-known
algorithms include the Manning Criteria, the obsolete Rome l and ll
criteria, and the Kruis Criteria, and studies have compared their reliability.
The more recent Rome lll Process was published in 2006. Physicians may choose to
use one of these guidelines or may simply choose to rely on their own anecdotal
experience with past patients. The algorithm may include additional tests to
guard against misdiagnosis of other diseases as IBS. Such "red flag" symptoms
may include weight loss, gastrointestinal bleeding, anemia, or nocturnal
symptoms. However, researchers have noted that red flag conditions may not
always contribute to accuracy in diagnosis; for instance, as many as 31% of IBS
patients have blood in their stool, many possibly from hemorrhoidal
bleeding.
The diagnostic algorithm
identifies a name that can be applied to the patient's condition based on the
combination of the patient's symptoms of diarrhea, abdominal pain, and
constipation. For example, the statement "50% of returning travelers had
developed functional diarrhea while 25% had developed IBS" would mean that half
the travelers had diarrhea while a quarter had diarrhea with abdominal pain.
While some researchers believe this categorization system will help physicians
understand IBS, others have questioned the value of the system and suggested
that all IBS patients have the same underlying disease but with different
symptoms.
Investigations
Investigations are performed to
exclude other conditions:
Stool microscopy and culture (to
exclude infectious conditions)
Blood tests: Full blood
examination, liver function tests, erythrocyte sedimentation rate, serological
testing for coeliac disease
Abdominal ultrasound (to exclude
gallstones and other biliary tract diseases)
endosopy and biopsies (to exclude
peptic ulcer disease, coeliac disease, inflammatory bowel disease,
malignancies)
Hydrogen breath testing (to
exclude fructose and lactose malabsorption)
Misdiagnosis
Published research has
demonstrated that some poor patient outcomes are due to treatable causes of
diarrhea being misdiagnosed as IBS. Common examples include infectious diseases,
coeliac disease, Helicobacter pylori, parasites.
Coeliac disease in particular is
often misdiagnosed as IBS. The American College of Gastroenterology recommends
that all patients with symptoms of IBS be tested for coeliac
disease.
Bile acid malabsorpton is
also often missed in patients with diarrhea-predominant IBS. SEHCAT tests
suggest that around 30% of D-IBS have this condition, and most respond to bile
acid sequestrants.
Chronic use of certain sedative
hypnotic drugs, especially the benzodiazepines, may cause irritable
bowel-like symptoms that can lead to a misdiagnosis of irritable bowel
syndrome.
Comorbidities
Researchers have identified
several medical conditions, or comorbidities, which appear with greater
frequency in patients diagnosed with IBS.
Headache, fibromyalgia, chronic
fatigue syndrome and depression: A study of 97,593 individuals with
IBS identified comorbidities such as headache, fibromyalgia, and
depression. A systematic review found that IBS occurs in 51% of chronic fatigue
syndrome patients and 49% of fibromyalgia patients, and psychiatric disorders
were found to occur in 94% of IBS patients.
inflammatory bowel disease IBD:
Some researchers have suggested that IBS is a type of low-grade inflammatory
bowel disease. Researchers have suggested that IBS and IBD are interrelated
diseases, noting that patients with IBD experience IBS-like symptoms when their
IBD is in remission. A three-year study found that patients diagnosed with IBS
were 16.3 times more likely to be diagnosed with IBD during the study period.
Serum markers associated with inflammation have also been found in patients with
IBS (see Causes).
Abdominal surgery: A 2008
study found that IBS patients were at increased risk of having unnecessary
cholecystectomy (gall bladder removal surgery) not due to an increased risk of
gallstones, but rather to abdominal pain, awareness of having gallstones, and
inappropriate surgical indications. A 2005 study reported that IBS patients are
87% more likely to undergo abdominal and pelvic surgery and three times more
likely to undergo gallbladder surgery. A study published in
Gastroenterology came to similar conclusions, and also noted IBS patients
were twice as likely to undergo hysterectomy.
endometriosis: One study
reported a statistically significant link between migraine headaches, IBS, and
endometriosis.
Other chronic disorders:
interstitial cystitus may be associated with other chronic pain syndromes, such
as irritable bowel syndrome and fibromyalgia. The connection between these
syndromes is unknown.
Management
A number of treatments have been
found to be better than placebo, including fiber, antispasmodics, and peppermint
oil.
Diet
Some people with IBS may have
food intolerances.
A low FODMAP diet has been shown
to reduce symptoms in functional GI disorders such as IBS by 60-80%. This diet
restricts various carbohydrates which are poorly absorbed in the small intestine
as well as fructose and lactose, which are similarly poorly absorbed in
those with intolerances to them. Reduction of fructose and frutan have been
shown to reduce IBS symptoms in a dose-dependent manner in patients with
fructose malabsorption and IBS. Many individuals with IBS are lactose intolerant
and a trial of a lactose-free diet is often recommended. Alternatively, an
over-the-counter remedy containing lactase enzyme can be taken before consuming
milk products. Allergy to milk products also causes diarrhea and other symptoms,
and this will not be improved by a lactase enzyme supplement. Many who benefit
from a low FODMAP diet need not restrict fructose or lactose.
Some IBS patients believe they
have some form of dietary intolerance; however, tests attempting to predict food
sensitivity in IBS have been disappointing. A small study reported that an IgG
antibody test was somewhat effective in determining food sensitivity in IBS
patients, with patients on the elimination diet experiencing 10% greater symptom
reduction than those on a sham diet. However, more research is necessary before
IgG testing can be recommended.
There is no evidence that
digestion of food or absorption of nutrients is problematic for those with IBS
at rates different from those without IBS. However, the very act of eating or
drinking can provoke an overreaction of the gastrocolic response in some
patients with IBS owing to their heightened visceral sensitivity, and this may
lead to abdominal pain, diarrhea, and/or constipation.
Fiber
There is some evidence that
soluble fiber supplementation (e.g., psyllium/ispagula husk) is effective in the
general IBS population. It acts as a bulking agent, and for many IBS-D patients,
it allows for a more consistent stool. For IBS-C patients, it seems to allow for
a softer, moister, more easily passable stool.
On the contrary, insoluble fiber
(e.g., bran) has not been found to be effective for IBS. In some people,
insoluble fiber supplementation may aggravate symptoms.
Fiber might be beneficial in
those who have a predominance of constipation. In patients who have IBS-C,
soluble fiber at doses of 20 grams per day can reduce overall symptoms but
will not reduce pain. The research supporting dietary fiber contains
conflicting, small studies that are complicated by the heterogeneity of types of
fiber and doses used.
One meta analysis found that only
soluble fiber improved global symptoms of irritable bowel, but neither type of
fiber reduced pain. An updated meta-analysis by the same authors also found that
soluble fiber reduced symptoms, while insoluble fiber worsened symptoms in some
cases. Positive studies have used 10–30 grams per day of psyllium. One
study specifically examined the effect of dose and found that 20 grams of
ispaghula husk was better than 10 grams and equivalent to 30 grams per
day. An uncontrolled study noted increased symptoms with insoluble fibers. It is
unclear if these symptoms are truly increased compared with a control group. If
the symptoms are increased, it is unclear if these patients were diarrhea
predominant (which can be exacerbated by insoluble fiber), or if the increase is
temporary before benefit occurs.
Psychotherapy
The mind-body or brain-gut
interactions has been proposed for irritable bowel syndrome and is gaining
increasing research attention. For some patients, psychological therapies may
help with symptoms. Cognitive behavioural therapy and Hypnosis have been
found to be the most beneficial. Hypnosis can improve mental well-being, and
cognitive behavioural therapy can provide psychological coping strategies for
dealing with distressing symptoms as well as help suppress thoughts and
behaviours that increase the symptoms of irritable bowel syndrome. Cognitive
behavioural therapy has been found to improve symptoms in a number of studies.
Relaxation therapy has also been found to be helpful.
A questionnaire in 2006 designed
to identify patients’ perceptions about IBS, their preferences on the type of
information they need, and educational media and expectations from health care
providers revealed misperceptions about IBS developing into other conditions,
including colitis, malnutrition, and cancer.
The survey found IBS patients
were most interested in learning about foods to avoid (60%), causes of IBS
(55%), medications (58%), coping strategies (56%), and psychological factors
related to IBS (55%). The respondents indicated that they wanted their
physicians to be available via phone or e-mail following a visit (80%), have the
ability to listen (80%), and provide hope (73%) and support
(63%).
Stress
relief
Reducing stress may reduce the
frequency and severity of IBS symptoms. Techniques that may be helpful
include:
Relaxation techniques such as
meditation
Physical activities such as yoga
or tai chi
Regular exercise such as
swimming, walking or running
Exercise
Many patients find that exercise
helps with IBS. At least 30 minutes of strenuous exercise 5 times a week is
recommended.
Alternative
medicine
Because of often unsatisfactory
results from medical treatments for IBS, up to 50 percent of people turn to
complementary alternative medicine.
Probiotics
Probiotics can be beneficial in
the treatment of IBS; taking 10 billion to 100 billion beneficial bacteria per
day is recommended for beneficial results. However, further research is needed
on individual strains of beneficial bacteria for more refined recommendations. A
number of probiotics have been found to be effective including: Lactobacillus
plantorum and bifidobacteria infantis;
however, one review found that
only bifidobacteria infantis showed efficacy. Some yogurt is made using
probiotics that may help ease symptoms of irritable bowel
syndrome.
Herbal
remedies
Peppermint oil: Enteric coated
peppermint oil capsules have been suggested for IBS symptoms in adults and
children.There is evidence of a beneficial effect of these capsules and it is
recommended that peppermint be trialed in all irritable bowel syndrome patients.
Safety during pregnancy has not been established, however, and caution is
required not to chew or break the enteric coating ; otherwise
gastroesophageal reflux may occur as a result of lower esophageal sphincter
relaxation. Occasionally nausea and perianal burning occur as side
effects.
Iberogast: The multi-herbal
extract lberogast was found to be significantly superior to placebo via both an
abdominal pain scale and an IBS symptom score after four weeks of
treatment.
Cannabis
Kiwifruit IBS/C
Commiphora mukul
Plantago ovate
There is only limited evidence
for the effectiveness of other herbal remedies for irritable bowel syndrome. As
with all herbs, it is wise to be aware of possible drug interactions and adverse
effects.
Yoga
Yoga may be effective for some
with irritable bowel syndrome, especially poses which exercise the lower
abdomen.
Acupuncture
Acupuncture may be worth a trial
in select patients, but the evidence base for effectiveness is weak. A meta
analysis by the Cochrane Collaboration found no benefits of acupuncture relative
to placebo for IBS symptom severity or IBS-related quality of
life.
diagnosis characterized by chronic abdominal pain, discomfort, bloating,
and alteration of bowel habits. As a functional bowel disorder, IBS has no known
organic cause. Diarrhea or constipation may predominate, or they may alternate
(classified as IBS-D, IBS-C or IBS-A, respectively).
Historically a diagnosis of exclusion, a diagnosis of IBS can now be made on the
basis of symptoms alone, in the absence of alarm features such as age of onset
greater than 50 years, weight loss, gross hematochezia, systemic signs of
infection or colitis, or family history of inflammatory bowel
disease. Onset of IBS is more likely to occur after an infection
(post-infectious, IBS-PI), a stressful life event, or onset of
maturity.
Although
there is no cure for IBS, there are treatments that attempt to relieve symptoms,
including dietary adjustments, medication and psychological interventions,
patient education and a good doctor patient relationship are also
important.
Several
conditions may present as IBS, including coeliac disease, fructose
malabsorption, mild infections, parasitic infections like giardiasis,
several inflammatory bowel diseases, bile acid malabsorption functional
chronic constipation, small intestinal bacterial overgrowth, and chronic
functional abdominal pain. In IBS, routine clinical tests yield no
abnormalities, although the bowels may be more sensitive to certain stimuli,
such as balloon insufflation testing. The exact cause of IBS is unknown. The
most common theory is that IBS is a disorder of the interaction between the
brain and the gastrointestinal tract, although there may also be abnormalities
in the gut flora or the immune system.
IBS has no
direct effect on life expectancy. It is, however, a source of chronic pain,
fatigue, and other symptoms and contributes to work absenteeism. The high
prevalence of IBS and significant effects on quality of life make IBS a disease
with a high social cost.It has also been suggested that a proportion of IBS
patients may develop depression and are thus more likely to commit suicide.
Proposed factors for increased suicide rate in IBS patients include perceived
hopelessness and poor quality of services.
Classification
IBS can be classified as either
diarrhea -predominant (IBS-D), constipation -predominant (IBS-C), or with
alternating stool pattern (IBS-A or pain-predominant). In some individuals, IBS
may have an acute onset and develop after an infectious illness characterized by
two or more of the following: fever, vomiting, diarrhea, or positive stool
culture, This post-infective syndrome has consequently been termed
"post-infectious IBS" (IBS-PI).
Signs
and symptoms
The primary symptoms of IBS are
abdominal pain or discomfort in association with frequent diarrhea or
constipation and a change in bowel habits. There may also be urgency for bowel
movements, a feeling of incomplete evacuation (tenesmus), bloating, or abdominal
distension. In some cases, the symptoms are relieved by bowel movements. People
with IBS, more commonly than others, have gastroesophageal reflux, symptoms
relating to the genitourinary system, chronic fatgue syndrome, fibromyalgia,
headache, backache and psychiatric symptoms such as depression and anxiety. Some
studies indicate that up to 60% of persons with IBS also have a psychological
disorder, typically anxiety or depression.
Causes
The cause of IBS is unknown;
several hypotheses have been proposed. The risk of developing IBS increases
sixfold after acute gastrointestinal infection. Postinfection, further risk
factors are young age, prolonged fever, anxiety, and depression. Publications
suggesting the role of brain-gut "axis" appeared in the 1990s, such as the study
"Brain-gut response to stress and cholinergic stimulation in IBS" published in
the Journal of Clinical Gastroenterology in 1993. A 1997 study published
in Gut magazine suggested that IBS was associated with a "derailing of
the brain-gut axis." Psychological factors may be important in the etiology of
IBS.
Active
infections
There is
research to support IBS being caused by an as-yet undiscovered active infection.
Studies have shown that the nonabsorbed antibiotic rifaximin can provide
sustained relief for some IBS patients.While some researchers see this as
evidence that IBS is related to an undiscovered agent, others believe IBS
patients suffer from overgrowth of intestinal flora and the antibiotics are
effective in reducing the overgrowth (known as "small intestinal bacterial
overgrowthsmall"). A 2012 study, which connected cultures of bacteria
from the small intestine to a significantly increased occurrence of IBS,
supports this hypothesis.
Other researchers have focused on
an unrecognized protozoal infection as a cause of IBS as certain protozoal
infections occur more frequently in IBS patients. Two of the protozoa
investigated have a high prevalence in industrialized countries and infect the
bowel, but little is known about them as they are recently emerged
pathogens.
blastocysis is a
single-cell organism that has been reported to produce symptoms of abdominal
pain, constipation and diarrhea in patients though these reports are contested
by some physicians. Studies from research hospitals have identified high
blastocystis infection rates in IBS patients, with 38% being reported from
London School of Hygiene & Tropical Medicine, 47% reported from the
Department of Gastroenterology at Aga Khan University in Pakistan and 18.1%
reported from the Institute of Diseases and Public Health at University of
Ancona in Italy. Reports from all three groups indicate a blastocystis
prevalence of approximately 7% in non-IBS patients. Researchers have noted that
clinical diagnostics fail to identify infection, and Blastocystis may not
respond to treatment with common antiprotozoals.
Dientamoeba Fragilis is a
single-cell organism that produces abdominal pain and diarrhea. Studies have
reported a high incidence of infection in developed countries, and symptoms of
patients resolve following antibiotic treatment. A 2002 study reported on a
large group of patients with IBS-like symptoms who were found to be infected
with Dientamoeba fragilis and experienced resolution of symptoms
following treatment. Researchers have noted that methods used clinically may
fail to detect some Dientamoeba fragilis infections. It is also found in
people without IBS
Diagnosis
There is no specific laboratory
or imaging test that can be performed to diagnose irritable bowel syndrome.
Diagnosis of IBS involves excluding conditions that produce IBS-like symptoms
and then following a procedure to categorize the patient's symptoms. Ruling out
parasitic infections, lactose intolerance, small intestinal bacterial
overgrowth, and celiac disease is recommended for all patients before a
diagnosis of irritable bowel syndrome is made. In patients over 50 years old, it
is recommended that they undergo a screening colonoscopy.
Differential
diagnosis
Colon cancer, inflammatory
bowel disease, thyroid disorders, and giardiasis can all feature abnormal
defecation and abdominal pain. Less common causes of this symptom profile are
carcinoid syndrome, microscopic colitis, bacterial overgrowth, and eosinophilic
gastroenteritis: IBS is, however, such a common presentation, and testing for
these conditions would yield such low numbers of positive results, that it is
considered difficult to justify the expense. Because there are many causes of
diarrhea that give IBS-like symptoms, the American Gastroenterological
Association published a set of guidelines for tests to be performed to rule out
other causes for these symptoms. These include gastrointestinal infections,
lactose intolerance, and coeliac disease. Research has suggested that these
guidelines are not always followed. Once other causes have been excluded, the
diagnosis of IBS is performed using a diagnostic algorithm. Well-known
algorithms include the Manning Criteria, the obsolete Rome l and ll
criteria, and the Kruis Criteria, and studies have compared their reliability.
The more recent Rome lll Process was published in 2006. Physicians may choose to
use one of these guidelines or may simply choose to rely on their own anecdotal
experience with past patients. The algorithm may include additional tests to
guard against misdiagnosis of other diseases as IBS. Such "red flag" symptoms
may include weight loss, gastrointestinal bleeding, anemia, or nocturnal
symptoms. However, researchers have noted that red flag conditions may not
always contribute to accuracy in diagnosis; for instance, as many as 31% of IBS
patients have blood in their stool, many possibly from hemorrhoidal
bleeding.
The diagnostic algorithm
identifies a name that can be applied to the patient's condition based on the
combination of the patient's symptoms of diarrhea, abdominal pain, and
constipation. For example, the statement "50% of returning travelers had
developed functional diarrhea while 25% had developed IBS" would mean that half
the travelers had diarrhea while a quarter had diarrhea with abdominal pain.
While some researchers believe this categorization system will help physicians
understand IBS, others have questioned the value of the system and suggested
that all IBS patients have the same underlying disease but with different
symptoms.
Investigations
Investigations are performed to
exclude other conditions:
Stool microscopy and culture (to
exclude infectious conditions)
Blood tests: Full blood
examination, liver function tests, erythrocyte sedimentation rate, serological
testing for coeliac disease
Abdominal ultrasound (to exclude
gallstones and other biliary tract diseases)
endosopy and biopsies (to exclude
peptic ulcer disease, coeliac disease, inflammatory bowel disease,
malignancies)
Hydrogen breath testing (to
exclude fructose and lactose malabsorption)
Misdiagnosis
Published research has
demonstrated that some poor patient outcomes are due to treatable causes of
diarrhea being misdiagnosed as IBS. Common examples include infectious diseases,
coeliac disease, Helicobacter pylori, parasites.
Coeliac disease in particular is
often misdiagnosed as IBS. The American College of Gastroenterology recommends
that all patients with symptoms of IBS be tested for coeliac
disease.
Bile acid malabsorpton is
also often missed in patients with diarrhea-predominant IBS. SEHCAT tests
suggest that around 30% of D-IBS have this condition, and most respond to bile
acid sequestrants.
Chronic use of certain sedative
hypnotic drugs, especially the benzodiazepines, may cause irritable
bowel-like symptoms that can lead to a misdiagnosis of irritable bowel
syndrome.
Comorbidities
Researchers have identified
several medical conditions, or comorbidities, which appear with greater
frequency in patients diagnosed with IBS.
Headache, fibromyalgia, chronic
fatigue syndrome and depression: A study of 97,593 individuals with
IBS identified comorbidities such as headache, fibromyalgia, and
depression. A systematic review found that IBS occurs in 51% of chronic fatigue
syndrome patients and 49% of fibromyalgia patients, and psychiatric disorders
were found to occur in 94% of IBS patients.
inflammatory bowel disease IBD:
Some researchers have suggested that IBS is a type of low-grade inflammatory
bowel disease. Researchers have suggested that IBS and IBD are interrelated
diseases, noting that patients with IBD experience IBS-like symptoms when their
IBD is in remission. A three-year study found that patients diagnosed with IBS
were 16.3 times more likely to be diagnosed with IBD during the study period.
Serum markers associated with inflammation have also been found in patients with
IBS (see Causes).
Abdominal surgery: A 2008
study found that IBS patients were at increased risk of having unnecessary
cholecystectomy (gall bladder removal surgery) not due to an increased risk of
gallstones, but rather to abdominal pain, awareness of having gallstones, and
inappropriate surgical indications. A 2005 study reported that IBS patients are
87% more likely to undergo abdominal and pelvic surgery and three times more
likely to undergo gallbladder surgery. A study published in
Gastroenterology came to similar conclusions, and also noted IBS patients
were twice as likely to undergo hysterectomy.
endometriosis: One study
reported a statistically significant link between migraine headaches, IBS, and
endometriosis.
Other chronic disorders:
interstitial cystitus may be associated with other chronic pain syndromes, such
as irritable bowel syndrome and fibromyalgia. The connection between these
syndromes is unknown.
Management
A number of treatments have been
found to be better than placebo, including fiber, antispasmodics, and peppermint
oil.
Diet
Some people with IBS may have
food intolerances.
A low FODMAP diet has been shown
to reduce symptoms in functional GI disorders such as IBS by 60-80%. This diet
restricts various carbohydrates which are poorly absorbed in the small intestine
as well as fructose and lactose, which are similarly poorly absorbed in
those with intolerances to them. Reduction of fructose and frutan have been
shown to reduce IBS symptoms in a dose-dependent manner in patients with
fructose malabsorption and IBS. Many individuals with IBS are lactose intolerant
and a trial of a lactose-free diet is often recommended. Alternatively, an
over-the-counter remedy containing lactase enzyme can be taken before consuming
milk products. Allergy to milk products also causes diarrhea and other symptoms,
and this will not be improved by a lactase enzyme supplement. Many who benefit
from a low FODMAP diet need not restrict fructose or lactose.
Some IBS patients believe they
have some form of dietary intolerance; however, tests attempting to predict food
sensitivity in IBS have been disappointing. A small study reported that an IgG
antibody test was somewhat effective in determining food sensitivity in IBS
patients, with patients on the elimination diet experiencing 10% greater symptom
reduction than those on a sham diet. However, more research is necessary before
IgG testing can be recommended.
There is no evidence that
digestion of food or absorption of nutrients is problematic for those with IBS
at rates different from those without IBS. However, the very act of eating or
drinking can provoke an overreaction of the gastrocolic response in some
patients with IBS owing to their heightened visceral sensitivity, and this may
lead to abdominal pain, diarrhea, and/or constipation.
Fiber
There is some evidence that
soluble fiber supplementation (e.g., psyllium/ispagula husk) is effective in the
general IBS population. It acts as a bulking agent, and for many IBS-D patients,
it allows for a more consistent stool. For IBS-C patients, it seems to allow for
a softer, moister, more easily passable stool.
On the contrary, insoluble fiber
(e.g., bran) has not been found to be effective for IBS. In some people,
insoluble fiber supplementation may aggravate symptoms.
Fiber might be beneficial in
those who have a predominance of constipation. In patients who have IBS-C,
soluble fiber at doses of 20 grams per day can reduce overall symptoms but
will not reduce pain. The research supporting dietary fiber contains
conflicting, small studies that are complicated by the heterogeneity of types of
fiber and doses used.
One meta analysis found that only
soluble fiber improved global symptoms of irritable bowel, but neither type of
fiber reduced pain. An updated meta-analysis by the same authors also found that
soluble fiber reduced symptoms, while insoluble fiber worsened symptoms in some
cases. Positive studies have used 10–30 grams per day of psyllium. One
study specifically examined the effect of dose and found that 20 grams of
ispaghula husk was better than 10 grams and equivalent to 30 grams per
day. An uncontrolled study noted increased symptoms with insoluble fibers. It is
unclear if these symptoms are truly increased compared with a control group. If
the symptoms are increased, it is unclear if these patients were diarrhea
predominant (which can be exacerbated by insoluble fiber), or if the increase is
temporary before benefit occurs.
Psychotherapy
The mind-body or brain-gut
interactions has been proposed for irritable bowel syndrome and is gaining
increasing research attention. For some patients, psychological therapies may
help with symptoms. Cognitive behavioural therapy and Hypnosis have been
found to be the most beneficial. Hypnosis can improve mental well-being, and
cognitive behavioural therapy can provide psychological coping strategies for
dealing with distressing symptoms as well as help suppress thoughts and
behaviours that increase the symptoms of irritable bowel syndrome. Cognitive
behavioural therapy has been found to improve symptoms in a number of studies.
Relaxation therapy has also been found to be helpful.
A questionnaire in 2006 designed
to identify patients’ perceptions about IBS, their preferences on the type of
information they need, and educational media and expectations from health care
providers revealed misperceptions about IBS developing into other conditions,
including colitis, malnutrition, and cancer.
The survey found IBS patients
were most interested in learning about foods to avoid (60%), causes of IBS
(55%), medications (58%), coping strategies (56%), and psychological factors
related to IBS (55%). The respondents indicated that they wanted their
physicians to be available via phone or e-mail following a visit (80%), have the
ability to listen (80%), and provide hope (73%) and support
(63%).
Stress
relief
Reducing stress may reduce the
frequency and severity of IBS symptoms. Techniques that may be helpful
include:
Relaxation techniques such as
meditation
Physical activities such as yoga
or tai chi
Regular exercise such as
swimming, walking or running
Exercise
Many patients find that exercise
helps with IBS. At least 30 minutes of strenuous exercise 5 times a week is
recommended.
Alternative
medicine
Because of often unsatisfactory
results from medical treatments for IBS, up to 50 percent of people turn to
complementary alternative medicine.
Probiotics
Probiotics can be beneficial in
the treatment of IBS; taking 10 billion to 100 billion beneficial bacteria per
day is recommended for beneficial results. However, further research is needed
on individual strains of beneficial bacteria for more refined recommendations. A
number of probiotics have been found to be effective including: Lactobacillus
plantorum and bifidobacteria infantis;
however, one review found that
only bifidobacteria infantis showed efficacy. Some yogurt is made using
probiotics that may help ease symptoms of irritable bowel
syndrome.
Herbal
remedies
Peppermint oil: Enteric coated
peppermint oil capsules have been suggested for IBS symptoms in adults and
children.There is evidence of a beneficial effect of these capsules and it is
recommended that peppermint be trialed in all irritable bowel syndrome patients.
Safety during pregnancy has not been established, however, and caution is
required not to chew or break the enteric coating ; otherwise
gastroesophageal reflux may occur as a result of lower esophageal sphincter
relaxation. Occasionally nausea and perianal burning occur as side
effects.
Iberogast: The multi-herbal
extract lberogast was found to be significantly superior to placebo via both an
abdominal pain scale and an IBS symptom score after four weeks of
treatment.
Cannabis
Kiwifruit IBS/C
Commiphora mukul
Plantago ovate
There is only limited evidence
for the effectiveness of other herbal remedies for irritable bowel syndrome. As
with all herbs, it is wise to be aware of possible drug interactions and adverse
effects.
Yoga
Yoga may be effective for some
with irritable bowel syndrome, especially poses which exercise the lower
abdomen.
Acupuncture
Acupuncture may be worth a trial
in select patients, but the evidence base for effectiveness is weak. A meta
analysis by the Cochrane Collaboration found no benefits of acupuncture relative
to placebo for IBS symptom severity or IBS-related quality of
life.
