Michael Margolin, MD, FACP, FACG  


Irritable bowel syndrome (IBS) refers to a common disorder of the lower intestinal tract. It involves abdominal pain and abnormal bowel movements. Emotional stress often makes the symptoms worse.

It is not the same as inflammatory bowel disease (IBD), which includes Crohn's disease and ulcerative colitis.


IBS involves a combination of abdominal pain and constipation, diarrhea, or an alternating pattern of these problems.

In IBS the intestinal nervous system becomes hypervigilant, with a lower tolerance for stretching and movement of the intestine, and a tendency for spasm of the intestinal muscles develops.  There is no problem with the structure of the intestine.

It is not clear why patients develop IBS, but in some instances, it occurs after an intestinal infection. This is called postinfectious IBS. There may also be other triggers.

IBS can occur at any age, but it often begins in adolescence or early adulthood. It is more common in women. The condition is the most common intestinal complaint for which patients are referred to a gastroenterologist.


Symptoms range from mild to severe. Most people have mild symptoms. IBS symptoms may be worse in patients who also have stress or mood disorders, such as anxiety and depression. However, it is important to understand that these conditions do not cause IBS.

Symptoms may include:

·         Abdominal distention

·         Abdominal fullness, gas, bloating

·         Abdominal pain that:

o        Comes and goes

o        Is reduced or goes away after a bowel movement

o        Occurs after meals

·         Chronic and frequent constipation, usually accompanied by pain

·         Chronic and frequent diarrhea, usually accompanied by pain

·         Emotional distress

·         Depression

·         Loss of appetite

Exams and Tests

Most of the time, your doctor can diagnose IBS with few or no tests. Tests usually reveal no problems. Some experts recommend a trial of a lactose-free diet for possible lactase deficiency.

Some patients may need an endoscopy, especially if symptoms begin later in life. Younger patients with persistent diarrhea may need this test to look for inflammatory bowel diseases that can cause similar symptoms, such as Crohn's disease or ulcerative colitis. You may need additional tests if you have blood in your stool, weight loss, signs of anemia, or you have recently traveled.

Patients over age 50 should be screened for colon cancer.


The goal of treatment is to relieve symptoms.

Lifestyle changes can be helpful in some people with IBS. For example, regular exercise, improved sleep habits, and stress reduction techniques may reduce anxiety and help relieve bowel symptoms.

Dietary changes can be helpful. However, no specific diet can be recommended for IBS in general, because the condition differs from one person to another. Increasing dietary fiber and avoiding foods and drinks that stimulate the intestines (such as caffeine, fatty foods, acidic foods, andbroccoli/cauliflower/brussel sprouts) may help some people.

Other possible treatments may include:

·         Fiber supplements or other medications to improve bowel movements

·         Probiotics (trying to restore a healthy balance of bacteria in the gut)

·         Medications for intestinal spasm

·         Counseling in cases of severe anxiety or depression

·         Antidiarrheal medications for those whose main symptom is diarrhea

·         Low-dose antidepressants to help relieve intestinal pain

Outlook (Prognosis)

Irritable bowel syndrome may be a lifelong condition for some people, but symptoms can usually be improved or relieved through treatment.  IBS does not increase the risk of cancer, ulcerative colitis or Crohn’s disease.






 ©  A.D.A.M., Inc. and Elsevier Inc. - www.mdconsult.com.  Modified by Michael Margolin, MD