Gastrointestinal malabsorptive procedures.

Morbid obesity is a complex disease, the etiology of which is clearly multifactorial. The weight loss produced by intestinal shunting procedures has been profound and the etiology of the weight loss is clearly more complex than rapid intestinal transit and gross malabsorption of foodstuffs. The best known surgically produced malabsorptive procedure for the treatment of morbid obesity is the jejunoileal bypass. This procedure produces substantial weight loss but has been associated with late postoperative complications that make its use problematical. Other procedures (biliary bypass, biliopancreatic diversion, and long limb Roux-en-Y gastric bypass) have not been associated with liver dysfunction. Varying degrees of malnutrition are frequently associated with these procedures. Careful study of the patients with these procedures is warranted.