Small bowel obstruction due to antegrade and retrograde intussusception after gastric bypass: three case reports in two patients, literature review, and recommendations for diagnosis and treatment.

Intestinal obstruction due to intussusception, although rare, is a complication that can cause small bowel obstruction after Roux-en-Y gastric bypass. Possible causes include disordered intestinal motility, the presence of staple lines and other lead points in the intestinal wall, and the anatomic peculiarities of the enteroenterostomy. In the case of antegrade intussusception, the lead point is usually identifiable and can involve either limb. Retrograde intussusception is more common but usually has a featureless entry point beginning a few inches below the intestinal anastomosis, with the intussusceptum traversing the enteroenterostomy into either the biliary or Roux limb. Abdominal computed tomography scan is necessary for diagnosis, and early exploration is recommended to avoid ischemia and bowel resection.