irritable bowel syndrome

irritable bowel syndrome A functional intestinal disorder of the bowels and their nerves. Irritable bowel syndrome (IBS) may be caused by either abnormal motility (abnormal contractions) of the intestinal muscles or abnormally sensitive nerves in the intestines (visceral hyper-sensitivity). IBS is characterized by abdominal pain, bloating, mucus in stools, and irregular bowel habits, with alternating diarrhea and constipation. These symptoms tend to be chronic, and they wax and wane over the years. Although IBS can cause chronic and recurrent discomfort, it does not normally lead to any serious organ problems. Diagnosis usually involves excluding other illnesses. Treatment is directed toward relief of symptoms. Also known as spastic colitis, mucus colitis, and nervous colon syndrome.