Overview of IBS

Irritable bowel syndrome (IBS), also known as spastic colon, is a digestive system disorder that presents as abdominal pain, bloating, cramping, excess mucus in stools, diarrhea, and constipation. It occurs mainly in the daytime and not during sleep, although in some patients the need to defecate may awaken them early in the morning.

Irritable bowel syndrome usually begins in the first three decades of life and may affect up to one-quarter of the population in industrialized countries. The exact etiology of irritable bowel syndrome is unknown, but stress, depression, hypersensitivity to certain hormones, and pressure from gas, diet, and medications may be contributing factors.

The syndrome is characterized by variable changes in the frequency and strength of muscular contractions in the intestines, which are responsible for moving digested food and, ultimately, feces through the gastrointestinal tract. Changes in frequency and contraction, and a patient's sensitivity to them, result in the classic symptoms of pain, diarrhea, or constipation. In most patients, irritable bowel syndrome shows a tendency toward diarrhea, constipation, or an alternation between the two.

Diagnosis usually is made after these symptoms have occurred for at least 3 months. Patients with these symptoms should have a complete examination to rule out diseases with similar symptoms, such as bacterial overgrowth, endometriosis, lactose intolerance, and celiac disease.

Treatment ranges from stress reduction and diet therapy to the use of antispasmodic drugs, antidepressants, and substances that regulate the amount of water in the intestines and prevent constipation and diarrhea. These treatments are palliative in nature.

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 01 Jan 2001

Last Modified: 22 Sep 2015