Irritable bowel syndrome

Irritable bowel syndrome often is called “spastic colon.”

It probably is the result of abnormal muscular activity of the intestinal wall. Chronic stress and depression may be the primary cause or at least contribute to flare-ups of symptoms.

IBS may begin with an infection such as acute gastroenteritis. However the exact cause is unknown. It occurs most often in those aged between 20 and 40 years, in more women than in men. About 7 percent of Americans suffer from IBS.

IBS is characterized by chronic abdominal pain, discomfort, bloating and alteration of bowel habits with frequent diarrhea or constipation in the absence of any detectable organic cause.

Persons with constipation may have pellet- or ribbon-like bowel movements. There may also be urgency for bowel movements and a feeling of incomplete evacuation. Typically, the symptoms occur after a meal and are temporarily relieved by a bowel movement.

People with IBS more commonly have gastroesophageal reflux, symptoms relating to the genitourinary system, chronic fatigue syndrome, fibromyalgia, headache, backache and psychiatric symptoms such as depression and anxiety. Some studies indicate that up to 60 percent of persons with IBS have a psychological disorder, typically anxiety or depression.

IBS is a diagnosis of exclusion. 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 50 years old or older it is recommended that they undergo a screening colonoscopy. An abdominal ultrasound may be necessary to rule out gall stones and other biliary tract diseases and endoscopy with biopsies to exclude peptic ulcer diseases, celiac diseases, inflammatory bowel diseases and malignancies.

Treatment of IBS depends greatly on a patient’s predominant symptoms. A high fiber diet decreases your chance of constipation and also decreases your risk of colon cancer. High fiber foods include whole-grain products, fruits, vegetables and legumes.

If you can’t tolerate high-fiber foods, bulking agents may be used in the form of psyllium (Metamucil) and possibly calcium polycarbophil.

Osmotic laxatives such as milk of magnesia as well as nonabsorbable polyethylene glycol, sorbitol, and lactulose are generally believed to be safer than stimulant laxatives. Stimulant laxatives such as senna and bisacodyl may be appropriate for intermittent use for constipated patients.

In IBS with diarrhea, loperamide (Imodium) is the only antidiarrheal agent that has been studied. Antispasmodic agents may reduce abdominal pain in the short term. Tricyclic antidepressants (Elavil) in smaller dosage may be used for pain. The short-term use of the nonabsorbed antibiotic rifaximin has demonstrated improvement in patients with IBS and diarrhea.

Probiotics such as Bifidobacteria infantis showed efficacy. For some patients psychological therapies may help. People with IBS often suffer in silence without taking their complaint to a physician.

It is important that you undergo a complete examination, particularly if the symptoms have appeared only recently, in order to be sure your problem is not being caused by something more serious.



By Bong J. Choi, M.D.



The author is a gastroenterologist and internist at the International Health Services of Samsung Medical Center. ― Ed.