[Weight gain after bariatric surgery].

Despite the frequent success of bariatric surgery, 20-30% of patients do not respond well. These patients may experience insufficient weight loss, defined as primary non-response, or may regain an excessive amount of weight after sufficient weight loss, defined as secondary non-response. The aetiology and subsequent treatment of these two types of non-response may differ. This is illustrated by three cases: a patient with primary non-response after gastric bypass (total weight loss 18%) treated conservatively; a patient with secondary non-response after gastric bypass (total weight loss 27%) treated conservatively and lost 7kg as a result of this therapy; a patient with secondary non-response after gastric bypass (total weight loss 27%) treated surgically though experienced malabsorptive complaints as result of distalisation. These cases can be used to demonstrate the challenges that are faced by professionals in the current treatment of post-bariatric surgery patients.