this type of surgery appeared at the same time as end-to-side jejunoileal bypass. some surgeons regarded this as a better option than end-to-side jejunoileal bypass because it prevented the reflux of ileal content to the blind loop. in order to achieve this, the end of the proximal duodenum is anastomosed to the distal ileum. the blind loop is drained to the transverse colon. however, two studies revealed that both end-to-side and end-to-end jejunoileal bypass had similar weight loss effect.