This study assessed the efficacy of self-induced vomiting and purgation, respectively, in attempts at preventing weight gain in patients with bulimia. It was found that the vomiters ate significantly more yet weighed less: the purgers ate less but weighed significantly more. Such findings strongly suggest that excess purgation has little impact on intestinal absorption even at the doses used in bulimia. Weight control appears to be exercised by dietary restraint not by the pharmacological action of the laxatives used.