Toxic megacolon: the knee-elbow position relieves bowel distension.

Toxic megacolon complicating inflammatory or infective colitis carries a high morbidity and mortality and surgical intervention is necessary in up to 80% of cases. Perforation complicates toxic megacolon in about 35% of cases. After perforation, the death rate nears 50%. Gaseous distension of the bowel causes considerable discomfort to the patient and increases transmural pressure. The latter is thought to cause a reduction in blood flow and may predispose to perforation. The use of instruments for colonic aspiration is discouraged, because of the high risk of perforation. The successful use of the knee-elbow position to relieve bowel distension in two patients with toxic megacolon is described.