Also known as tympanites, this is a distension of the ABDOMEN from excess gas or air in the INTESTINE or peritoneal cavity. On percussion (tapping) the abdomen sounds resonant, like a drum. Causes include aerophagy (the swallowing of air), IRRITABLE BOWEL SYNDROME (IBS) and, uncommonly and usually associated with vomiting and absolute constipation, obstruction of the intestines. Treatment is of the underlying condition. (See also FLATULENCE.)