Irritable bowel syndrome (IBS) is a common though uncomfortable disorder of the colon or rectum. While the basic cause of IBS is unknown, researchers have found that the colon muscle in people with IBS contracts more readily than in people without IBS. A number of factors can "trigger" IBS, including certain foods, medicines and emotional stress. IBS is not a life-threatening condition and does not make a person more likely to develop other colon conditions, such as colitis, Crohn’s disease or colon cancer.

Symptoms of IBS include abdominal pains or cramps, usually in the lower half of the abdomen; excess gas; or harder or looser bowel movements than average. Symptoms of IBS DO NOT include bleeding or black stools.

Inflammatory bowel disease (IBD) most often refers to Crohn’s disease and ulcerative colitis, but also may be referred to as colitis, enteritis, ileitis and proctitis. Both Crohn’s disease and ulcerative colitis cause inflammation of the bowel.

Crohn’s disease is a chronic illness in which the intestine (bowel) becomes inflamed and ulcerated (marked with sores). Crohn’s disease typically begins in the lower part of the small intestine (ileum), although it can occur in any part of the large or small intestine, stomach or esophagus. Crohn’s disease affects the entire thickness of the walls of the bowel, explaining why patients with Crohn’s disease are prone to developing fistulas and abscesses. In addition, sections of diseased bowel can be interrupted by sections of healthy bowel.

The symptoms of Crohn’s disease depend on where the disease occurs in the bowel and its severity. In general, symptoms include: chronic diarrhea, weight loss, fever, abdominal pain and tenderness (often on the right side of the lower abdomen) and feeling of a mass or fullness in the lower, right abdomen.

Ulcerative colitis occurs only in the large intestine and typically follows an unbroken pattern. Ulcerative colitis affects only the large intestine. It does not affect the esophagus, stomach or the small intestine. It affects only the inner layer of the colon (mucosa), and does so in a continuous pattern. The inflammation begins in the rectum and then spreads to other segments of the colon.

The main symptom of ulcerative colitis is diarrhea which subsequently becomes bloody. Occasionally the symptoms of ulcerative colitis include severe bloody diarrhea, abdominal pain and fever.

If you suspect you have IBS or IBD, it is important to see your doctor. Your doctor should review your medical history and perform a physical examination. The medical history is especially important for the Crohn’s disease diagnosis, since the disease is more common in people who have a first-degree relative with IBS. To diagnose IBD, one or more of the following tests may be ordered: blood tests, stool samples, endoscopic examination of the colon with biopsies, barium X-ray (barium enema).