Megacolon

Abstract

Megacolon is a disorder of both colonic structure and function in which gross dilation of the large intestine and inability to evacuate fecal material results in severe chronic constipation or obstipation. It describes a clinical condition with many possible etiologies, rather than a distinct disease entity. The most common presentation of primary megacolon is idiopathic megacolon in cats. The underlying pathophysiology of megacolon can be divided functionally into colonic inertia or outlet obstruction. Canine megacolon is diagnosed much less frequently than feline megacolon. The clinical history and physical examination findings are highly suggestive of a diagnosis of megacolon. Inflammatory bowel disease (IBD) may be present concurrently with megacolon. Medical therapy is indicated prior to surgical intervention in mild cases of megacolon. There are several anastomotic methods available to reestablish continuity of the gastrointestinal tract after subtotal colectomy.