Bowel obstruction is a very rare complication of sleeve gastrectomy and laparoscopic adjustable gastric banding but has been reported to have an overall incidence of up to 5 % in patients after laparoscopic Roux-en-Y gastric bypass (LRYGB) [1]. Similar to other types of bowel obstruction, patients present with abdominal pain, nausea and vomiting, and minimal or no bowel function.

Diagnosis of small bowel obstructions is made clinically, and with the help of CT scans, small bowel follows through or upper GI series. Causes of obstructions such as internal hernias can be missed on the imaging studies and present with vague symptoms, so there should be a very low threshold for taking the patient to the operating room.

Obstructions can be early or late. Early post-operative small bowel obstructions tend to result from technical problems with the Roux limb and require revision of the bypass or small bowel resection [2]. Early small bowel obstructions are more frequently treated operatively than late obstructions. Also, in the very immediate postoperative period, acute stenosis at the gastrojejunal anastomosis may develop secondary to surrounding tissue edema. In these cases, nasogastric decompression and bowel rest may be helpful until resolution of the edema and stenosis occurs. It is very important to properly diagnose technical problems because they can cause grave consequences for the patient if not fixed in timely manner.

Etiologies of late small bowel obstruction include adhesions, internal hernias, abdominal wall hernias, and intussusceptions [3]. Adhesions are most commonly seen after open gastric bypass surgery. Internal hernias are more frequently seen after laparoscopic procedures and have an incidence of 3–16 % [4]. They occur when portions of the small bowel slip through defects in the mesentery created during surgery. This results in obstruction of the blood supply and ischemia. They are extremely difficult to diagnose because of nonspecific symptoms such as cramping, periumbilical pain, nausea, and vomiting. Also diagnostic radiographic studies can be normal, or have very subtle findings such as mesenteric edema or englarged mesenteric lymph nodes. Low threshold for re-exploration is indicated in bariatric patients with unexplained pain or symptoms of bowel obstruction because internal hernias sometimes can be missed on radiologic studies.

Incisional hernias were reported to be the most frequent late complication in open gastric bypass, occurring in 8.6–20 % of patients [1]. In the era of laparoscopic surgery, this is drastically less.