Megacolon and Pseudo-Obstruction

The term megacolon refers to colonic dilatation. Acutely and chronically, it may be due to obstruction. When it is not, it is described as acute colonic pseudo-obstruction (Ogilvie syndrome) or chronically as chronic intestinal pseudo-obstruction (CIP). Acute colonic pseudo-obstruction is a common complication of major surgery and severe illnesses. Non-obstructive chronic megacolon has been described in association with a number of neurological conditions that may also occur as an idiopathic disorder. Chronic intestinal pseudo-obstruction (CIP) is an uncommon disorder that may involve nerve or muscle of any part of the gastrointestinal tract and usually occurs in the context of a systemic connective tissue disorder or neurological disease. The differentiation of CIP from organic obstruction may prove challenging and specialized methods such as intestinal manometry and full-thickness biopsies may be required. The management of megacolon is dictated by the risk of perforation and that of CIP includes symptomatic measures as well as attention to complications and malnutrition, in particular.