Irritable Bowel Syndrome
Stephen R. Freeman, M.D.
Associate Professor of Medicine
University of Colorado Denver Health Sciences Center
Department of Medicine- Gastroenterology
Anschutz Outpatient Pavilion
Irritable Bowel Syndrome (IBS) is a very common
condition affecting people worldwide and is manifest,
and indeed, defined by, symptoms of abdominal pain
and discomfort, and altered bowel habits and stool
form. It is primarily a condition affecting young adults,
but also affecting children, and women more so than
men. The acronym IBS should not be confused with
another common, but more serious digestive disease,
IBD or inflammatory bowel disease, a disease
associated with an inflammation of the colon or small
intestine. IBS is characterized as constipation
predominant, diarrhea predominant and mixed
types. IBS is one of many human conditions defined
by symptoms and the absence of “alarm” symptoms or
signs, and these are outlined in a widely agreed upon
and scientifically validated set of criteria known as the
Rome criteria*. IBS diagnostic criteria are:
Recurrent abdominal pain or discomfort at least 3 days/month in the last
3 months associated with two or more of the following:
1. Improvement with defecation
2. Onset associated with a change in frequency of stool
3. Onset associated with a change in form (appearance) of stool
These criterions have to be met within the past 3 months and have to have
had the onset of symptoms at least 6 months prior to the diagnosis.
“Alarm” symptoms or signs are potentially more worrisome problems that might
imply a more serious underlying diagnosis, and therefore might mean more testing
should be done to look into these symptoms. Examples of such “alarm” symptoms or
signs are:
1. Onset at older age > 60 yrs
2. More severe diarrhea: > 6 bowel movements/ day
3. Rectal bleeding
4. Unintentional weight loss
5. Iron deficiency anemia
6. Family history (1st degree relative) of colon or ovarian cancer
7. Family history of celiac disease
8. Nocturnal symptoms
9. Abdominal or rectal mass
*The Rome criteria were developed to try to identify similar patients for purposes of clinical research, but have
been helpful to physicians in making the correct diagnosis of IBS and in the appropriate treatment of these patients.
Page 1 of 5 Created by The Women’s Integrated Services in Health Program Content written by Dr. Stephen Freeman MD /10/2011
The cause of IBS is not known but it appears to be a motility disorder associated with
neurologic or muscular hypersensitivity of the colon. This hypersensitivity is also
referred to as visceral hyperalgesia and is felt to be usual or normal events occurring
in the usual function of the colon causing pain and dysfunction in certain individuals.
Other stimuli applied to other parts of the body may also be associated with a
heightened pain response in these individuals. An area of controversy exists
regarding the role of bacteria in causing IBS symptoms. There is some medical
evidence supporting the theory that overgrowth of intestinal bacteria in the small
bowel may cause some symptoms of abdominal discomfort and bowel irregularity,
and might respond to antibiotic treatment. The methods of testing for this are
inaccurate and often misleading, and the treatment is at best temporary, and will
alter bacteria in the colon also which also often will give temporary benefit.
A risk factor for developing IBS includes having an acute gastrointestinal infection
such as “traveler’s diarrhea” or viral gastroenteritis. Other possible risk factors are
aerophagia (air swallowing) associated with reflux or postnasal drainage and
antibiotic use for non-gastrointestinal conditions. In addition, there are a number of
potentially modifiable childhood conditions that seem to be risk factors for IBS
continuing or developing in adult patients. There are no associated risks for
developing IBS from other factors known to be a risk for other serious health
problems, specifically smoking, alcohol use, and coffee.
There are also several conditions affecting adult patients that are associated with IBS
including fibromyalgia, anxiety and depression, migraine headaches, sleep disorders
and a variety of other physical diseases such as asthma, recurrent urinary tract
infections, diverticulosis, and previous surgeries like hysterectomy and
cholecystectomy.
Diagnosis of IBS is based on compatible symptoms and absence of “alarm”
symptoms or signs. It is common and usually necessary for some basic testing to be
done, mostly blood tests, occasionally other tests like x-rays or, sometimes,
endoscopic tests. For the most part, a patient with these symptoms and normal basic
tests do not have to undergo a large number of tests to be accurately diagnosed. Of
course, there are patients with atypical or more severe symptoms who require more
extensive testing before the diagnosis is made. One of the most important diseases
to consider in patients felt to have IBS is celiac sprue, as symptoms of both
conditions can frequently overlap, and there is a very specific treatment for celiac
disease, namely a gluten free diet. This same treatment is not usually necessary in
IBS, although may, at times, be helpful.
Treatment of Irritable Bowel Syndrome is aimed at the particular symptoms a patient
has and there is no one treatment for this condition. What helps one person may not
help the next person. Treatment is often by “trial and error”. While there is no cure
for IBS, this condition does tend to wax and wane over time and may seem to recede
and not bother the person for sometimes long periods of time. Whereas IBS tends to
first make its appearance in young people from children to young adults, it may
continue to affect susceptible patients well into their middle or older age years. It is
quite uncommon for this condition to have its onset after the age of 50 – 60, and
symptoms compatible with IBS beginning in these years clearly deserves to be
diagnosed with more caution and more testing done to look for other more serious
diseases.
Page 2 of 5 Created by The Women’s Integrated Services in Health Program Content written by Dr. Stephen Freeman MD /10/2011
Fiber bulking agents are commonly used to improve bowel irregularity problems.
They generally tend to be helpful for both diarrhea and constipation types of IBS, but
are more useful in the constipation-predominant type. Dietary fiber like wheat bran
is an example of insoluble fiber, and a fiber supplement such as psyllium husk is an
example of a soluble fiber. Generally speaking the soluble fibers are more helpful in
relieving the global symptoms of IBS and the insoluble fibers are better for the
treatment of IBS-related constipation. The soluble fibers are sometimes better
tolerated than the insoluble varieties, as the latter may be more subject to bacterial
action and production of gas within the colon which can contribute to IBS-related
abdominal discomfort.
Dietary Suggestions for IBS
o
o
o
o
o
o
o
o
o
o
o
o
o
o
Eat regularly and take time to eat
Drink 8 or more cups of fluid daily, especially water or other non-caffeinated
drinks
Limit tea and coffee to 3 or fewer cups daily
Reduce consumption of alcoholic and carbonated beverages
Limit high-fiber foods such as whole grain breads, cereals high in bran, and whole
grains such as brown rice
Reduce consumption of ‘resistant starch’ (starch that resists digestion in the small
intestine and reaches the colon intact such as wheat and wheat-containing
products), which is often found in processed or re-cooked foods
Limit fresh fruit intake to less than 240 g daily
People with gas and bloating may find it helpful to incorporate oats and linseeds
(up to 1 tablespoon per day) in their diet
People with diarrhea should avoid sorbitol
Keep food diary to determine how food affects symptoms
Avoid large meals
Reduce fat to no more than 40-50 g daily
Avoid foods which may increase gas, such as legumes and cruciferous vegetables
Reduce fermentable oligo-, di- and monosaccharide’s and polyols
Physical exercise or increased physical activity has been associated with decreased
IBS symptom severity. Counseling may be helpful in certain patients with IBS.
Cognitive behavioral therapy, hypnotherapy, and/or psychological therapy are a
consideration for patients who do not respond to dietary and pharmacological
treatments after 12 months and have continuing debilitating symptoms. This
generally involves a small minority of IBS patients.
Pharmacologic therapies are also available and consist if a few different categories of
medications with varying degrees of effectiveness.
For constipation, several laxatives that are helpful include the bulking agents, as
well as ones that promote stool hydration such as docusate sodium, PEG electrolyte
solution, and other osmotic laxatives which are available over the counter. Most of
these are most effective if used daily for a period of time rather than sporadically.
Page 3 of 5 Created by The Women’s Integrated Services in Health Program Content written by Dr. Stephen Freeman MD /10/2011
Anti-diarrheal medications for diarrhea-predominant IBS are safe to use as needed,
including loperamide and kaopectate. Prescription medications are also effective such
as diphenoxalate – atropine and alosetron.
For pain control, avoidance of potentially addictive narcotic analgesics is generally
advisable. Anti-depressants are quite useful as pain modulators as well as treatment
for any associated depression or anxiety. These can be tricyclic antidepressants
(TCAs) such as nortriptyline or some of the newer serotonin re-uptake inhibitors
(SSRIs) such as Paxil and Zoloft. Pain from smooth muscle spasm may respond to
anti-spasmodics such as hyoscyamine or dicyclomine. Another medication that may
be helpful for spasm is peppermint oil, such as in an Altoid mint.
Antibiotics can be used to treat small bowel bacterial overgrowth, and generally can
be temporarily effective for abdominal discomfort or bloating, and possibly even
constipation. These effects are temporary, but can last for a few weeks following
stopping the antibiotic. Most antibiotics used for this purpose are ones which are
nonabsorbable such as rifaxamin or neomycin. The risk of antibiotics is the creation
of gut organisms which become resistant to these antibiotics, or which allow the
overgrowth of harmful bacteria and allow the development of serious infectious
colitis such as Clostridia difficile colitis.
Probiotics are the pharmacologic use of nonharmful, and potentially useful bacterial
organisms to try to repopulate the gut with flora that might be helpful in eliminating
noxious symptoms such as constipation, diarrhea, bloating and other abdominal
discomfort. There are many small studies which show some benefit from this
treatment, but, unfortunately, the weight of the evidence shows that probiotics are
not any better than placebo in treating IBS symptoms. The good news is that
placebo has always, in many trials of various treatments for IBS symptoms, been a
very good treatment with surprisingly high response rates. This phenomenon has
made proving efficacy of many IBS drug treatments difficult when appropriately
compared to the placebo response.
One other aspect of treatment of IBS symptoms that has been found to be effective
is a good provider – patient relationship. Having a comfort level and confidence in
your provider has been proven to be quite helpful in the successful management of
even difficult patients with IBS.
Irritable bowel syndrome is a common condition affecting millions of people
worldwide of all ages and sexes. It is not a life threatening condition but does cause
pain and discomfort, and can be costly in terms of loss of time and productivity from
usual activities, and significant medical costs. At times, the symptoms can also cause
alterations in usual lifestyle preferences. It is a complex condition, not yet well
understood, but clearly involves a relationship between the central and gut
neuromuscular systems and interaction between our environment and our bodies.
This interaction is multifactorial including diet, medications, other medical conditions,
and, importantly, internalized and external stress factors. Management is directed
toward symptom control through a variety of means, many of which are imperfect
and give incomplete results. Insight into the nature of the problem and its causes
and treatments and setting appropriate expectations is an important factor in helping
a person cope with this condition.
Page 4 of 5 Created by The Women’s Integrated Services in Health Program Content written by Dr. Stephen Freeman MD /10/2011
Guidelines
1.
2.
3.
4.
NICE 2008 Feb:CG61 PDF
National Guideline Clearinghouse 2009 May 4:13703
BMJ 2008 Mar 8;336(7643):556
Am J Gastroenterol 2009 Jan;104 (Suppl 1):S1
Reviews
1.
2.
3.
4.
5.
J Fam Pract 2008 Feb;57(2):100
N Engl J Med 2008 Apr 17;358(16):1692
Altern Ther Health Med 2004 May-Jun;10(3):22
BMJ 2005 Mar 19;330(7492):632 full-text
N Engl J Med 2003 Nov 27;349(22):2136
About the Doctor
Stephen R. Freeman, M.D.
Associate Professor of Medicine
University of Colorado Denver Health Sciences Center
Department of Medicine- Gastroenterology
Anschutz Outpatient Pavilion
Dr. Freeman received his medical degree from the University of
Arkansas, Medical Sciences College of Medicine. He completed his
internship and residency with the Tripler Army Medical Center
program. Dr Freeman is dual board certified in Internal Medicine
and Internal Medicine-Gastroenterology.
He see’s patients at the University of Colorado Hospital. Dr Freeman’s clinical
interests include Gastrointestinal Motility disorders, Gastroesophageal Reflux and
other Peptic diseases. He is an expert in Inflammatory Bowel Disease and Colorectal
Cancer.
For more information about The Women’s Integrated Services in Health (WISH)
Call 720-848-9474 or go to www.wishforwomen.org
Your WISH team can help make a referral to the Gastroenterology Services at the
University of Colorado Hospital
For more information about The Services for Colorectal Screening and the
Gastroenterology team at the University of Colorado Hospital visit our website.
Call 720-848-2777 to schedule an appointment.
Page 5 of 5 Created by The Women’s Integrated Services in Health Program Content written by Dr. Stephen Freeman MD /10/2011