Appetitive behavior after jejunoileal bypass.

There is now extensive evidence that jejunioleal bypass (JIB) surgery reduces food intake in obese patients, and that in most cases this is the primary cause of their postoperative weight loss. Associated with the reduced food consumption are other behavioral changes, including alterations in meal patterns, appetite ratings, taste responsiveness, and food-related attitudes. Experimental animal research indicates that JIB surgery also reduces food intake in obese rats and alters their feeding patterns. The hypophagia and weight loss produced by the surgery in rats is dependent upon both the degree and type of obesity. The exact mechanism(s) by which JIB surgery suppresses food intake remains to be determined, although recent animal research implicates both visceral malaise and overstimulation of the lower ileum as contributing factors.