Small bowel obstruction are more frequent after laparoscopic gastric bypass than after open procedures. Most obstructions after laparoscopic Roux-en-Y gastric bypass are secondary to internal hernias, with fewer obstructions from post-operative adhesions or other causes.

Small bowel obstruction may occur anywhere and produce varied radiographic appearances.

Roux limb obstructions may be secondary to adhesions, strictures, kinking, internal hernias, or occasionally bezoars or intussusceptions. Patients with Roux limb obstructions typically present with nausea and vomiting, and radiologic evidence of obstruction may be detected at UGI examination or CT.