Of 504 biliopancreatic diversions, 37 patients (7%) had to be reversed. There were many underlying causes for the nutritional compromise that preceded each reversal, but nearly two-thirds were due to either the nausea/hyperemesis syndrome or to protein malnutrition and anemia. Poor patient compliance with respect to supplements was a major contributory factor. The procedure can be reversed by either a proximal enteroenterostomy or restoration of anatomical continuity. The simpler enteroenterostomy, the method of choice, was done in 70% of the cases. There are specific indications for the more complex anatomical restoration. Reversals have proved to be successful in correcting the nutritional defects.