Background: Although unusual, but not rare, obstruction in the vicinity of the jejunojejunostomy in Roux-Y gastric bypass (RYGBP) can progress in a very short period of time to a life-threatening situation. Methods: Over a 10-year period in 1,174 RYGBP's, we have seen seven instances of acute and subacute partial to complete small bowel obstructions in the vicinity of the jejunojejunostomy, which can lead to acute gastric dilatation due to obstruction of the bilio-pancreatic limb. Signs and symptoms of the obstruction may include tachycardia, oliguria, hypotension, severe epigastric pain with or without a palpable mass in the epigastrium, chronic bile regurgitation and bilious vomiting, and a possible increase in serum amylase. Laboratory data otherwise has not been helpful, and although a palpable abdominal mass may be diagnostic, the best tools have been radiologic, i.e. the acute abdomen series, limited upper GI series in the patients that appear to be only partially obstructed, abdominal ultrasound and probably most importantly, CT of the abdomen. Results: In the seven cases presented, diagnoses included internal hernia, adhesions, an idiopathic spontaneous hematoma of the bowel wall and retrograde intussusception at the jejunojejunostomy. Conclusions: Since many surgeons who perform bariatric surgery are alone in their community, they should train their non-bariatric surgical colleagues and associates to be aware of these potential deadly problems.