Biliopancreatic diversion with duodenal switch Photo Biliopancreatic diversion with duodenal switch (BPD/DS) is like gastric bypass. Rather than a small stomach pouch, the specialist makes a sleeve- shaped stomach. The specialist then attaches final section of the small intestine to the stomach sleeve. The small intestine ingests calories and nutrients. Bypassing everything except the last section of the small intestine guarantees that far less calories are ingested. Removed portion of the stomach implies fewer hunger-causing hormones are secreted, making patient to feel less hungry generally.