A recent review of the results of gastroplasties done at the University of Alberta Hospital showed that there was a high incidence of late weight loss failure. Therefore a new operation, gastroplasty/distal gastric bypass, has been performed on 263 patients. This operation results In a profound (mean greatest percentage excess weight loss of 87% at approximately 2 years) and lasting weight loss (mean final percentage excess weight loss of 78%) at 4 years, range 2-7.5 years post-operatively. Only 0.9 % of patients failed to maintain at least a 40% excess weight loss. The operation achieves its effect through a moderate restriction that permits patients to eat normal table food from the time of discharge and with a mild metabsorption that is not ordinarily associated with diarrhea or notable deficiencies. Certain patients required debanding of the stoma and others developed staple-line eventration. Neither of these events after long-term follow-up resulted in weight loss failure nor in other serious side-effects. It Is concluded that moderate failure of the gastroplasty stoma and staple line does not necessarily result in weight loss failure, because the malabsorptive portion of the operation remains intact. Low hemoglobin occurred in 16% of cases and deficiency of serum iron In 34%; a much smaller number of patients had chronic or Intermittent deficiencies of these entities. Correction was easily achieved with oral replacement. Deficiencies in albumin, calcium, phosphorus and folate were rarely seen and minimal elevation of serum AST values occurred In just over 1% of patients. Chronic deficiencies or elevations were not seen in these patients. Stomal ulcer occurred in 6% of patients and bleeding associated with stomal ulcer in 1%. Half the patients with ulcer were managed with H&inf2; blockers, the other half with vagotomy. Both forms of treatment when individualized effectively prevent re-ulceration.