Gastrointestinal leak after gastric bypass is a known complication. Its incidence is between 1 and 5 %, and it is associated with a mortality rate of 6–15 % [1]. A leak doubles the risk of mortality and results in a sixfold increase in hospital stay [2]. Patients who develop a leak are at increased risk for wound infection, sepsis, respiratory failure, renal failure, thromboembolism, internal hernia, and small bowel obstruction.

Leaks often present without fever, leukocytosis, or pain. The most common reported symptom of leak is tachycardia; it is present in 72–92 % of patients [3]. There are also studies that report nausea, vomiting, fever, and leukocytosis. A Leak needs to be on the differential diagnosis with any of the symptoms above.

Diagnosis of a leak can be made radiologically or endoscopically. Upper gastrointestinal series with water-soluble contrast and computed tomography (CT) scans have limited sensitivity because of body habitus but high positive predictive value [3]. The weight limitations for CT and MRI scanners in a regular hospital facility range from 135 to 200 kg (300–450 lbs.). CT scanners that can accommodate patients of up to 350 kg body weight (800 lbs) are available but are very expensive and therefore not purchased by most hospitals. For that reason, surgeons performing bariatric surgery should know the weight limitations of the radiology equipment in their facility because some patients are expected to exceed the body weight limitations. Additionally, patient weight has a large effect on enhancement by intravenous contrast material both in the vascular system and in parenchymal organs such as the liver. Nevertheless, computerized tomography of the abdomen after gastric bypass can detect leaks, abscesses, internal hernias, and bowel obstruction. Other limitations of CT are patient positioning and the inability to ingest adequate oral contrast secondary to nausea and vomiting. Because of all of the reasons discussed above, CT has not consistently demonstrated a high level of sensitivity in detecting early postoperative leaks.

Upper GI contrast examination is utilized by many surgeons to evaluate the gastrojejunostomy in patients with suspected leak after gastric bypass. Numerous factors may influence the accuracy of such testing including patient‐related factors such as the ability to stand, balance, move about, and swallow and the size of the patient. Sensitivity of upper GI contrast examination varies among reports between 22 and 75 % [3].

When a leak is suspected, endoscopic investigation is warranted. Endoscopic procedures involve the examination of the esophagus, stomach, and gastric pouch (in gastric bypass). During endoscopic examination under fluoroscopy, a bubble test such as submerging the stomach while endoscopically insufflated (bubbles indicate presence of a leak) and injection of contrast with methylene blue into an abdominal drain while looking endoscopically and fluoroscopically for evidence of leak can be performed. These tests are very sensitive for gastric leak [4].

The management of patients with postoperative leak is very challenging because of multiple conditions including the time since the surgical procedure, the type of surgical procedure, and the stability of the patient. Surgical management is associated with high morbidity and mortality. Therefore, initial management is conservative or endoscopic. It begins with supportive care, placing patient nothing by mouth, ordering parenteral or distal enteral feeding, and adding broad-spectrum antibiotics to current medications and percutaneous drainage of any collections found on imaging studies [5].