A Rare Case of Gastrocolic Fistula Secondary to Marginal Ulcer Following Mini Gastric Bypass

Dar R, Zeina AR AR and Sakran N

Published on: 2021-04-22


Mini Gastric Bypass (MGB) is a simple, safe, feasible, and efficient weight loss reducing surgery, and rapidly gaining popularity, and is now the third most common bariatric surgery performed worldwide. Complications following MGB are common. Some of these complications may be life-threatening and require prompt diagnosis, intervention, and revisional surgery. Of these, marginal ulcers (MU) are a major cause of morbidity following MGB. Patients need surgical intervention after MU diagnosis for complications such as bleeding, perforation, stricture, and gastric fistulas. Gastro-colic fistula (GCF) is a rare clinical disorder that most often occurred after gastric surgery or a locally advanced tumor. However, during the last decade, an increasing number of GCFs were described as a complication of benign gastric ulcers. This case explains the rare and challenging scenario of gastro-colic fistula after laparoscopic MGB.   


Marginal Ulcer; Mini Gastric Bypass; Gastrocolic Fistula; Bariatric Surgery


Mini Gastric Bypass (MGB) is gaining acceptance as the preferred option for treating obesity [1, 2]. Less than 5% of patients after MGB may require revisional surgery. Of these revisions, half are performed due to severe malnutrition, and the other half due to bile reflux, marginal ulcer (MU), or weights regain [3]. There is still a scarcity of literature regarding GCF as a complication of MGB, and available data is mostly comprised of case studies. In a review, Tashiro et al. reported that among 181 cases of GCF, only 15 were caused by gastric ulcer [4]. The reported incidence of marginal ulcers after gastric bypass surgery varies widely (0.6-6?%), and pathogenesis is unclear [5-8]. Risks of marginal ulcers and subsequent fistula after MGB still present significant concerns in clinical practice. Approximately 17% of patients need surgical intervention after a diagnosis of MU over the ensuing eight years for complications such as bleeding, perforation, stricture, and gastro-gastric fistula [5]. Some of these can be life-threatening [6-8]. The MU usually occurs on the jejunal side of the gastro-jejunal anastomosis. Several risk factors seem to have an impact on the development of MUs. They include poor tissue perfusion due to tension or ischemia at the anastomosis, the presence of foreign material such as staples or non-absorbable suture, excess acid exposure in the gastric pouch, the use of nonsteroidal anti-inflammatory medications, tobacco, comorbidities such as diabetes mellitus or Helicobacter pylori infection; and enlarged pouch size [9]. When a gastro-colic fistula is formed, fecal matter thereby passes improperly from the colon to the stomach and causes halitosis. Symptoms may be variable and intermittent because of temporary plugging of the fistula. The most common presenting symptoms are diarrhea, abdominal pain, weight loss, vomiting followed by anemia, and foul-smelling eructation. Fecal vomiting with resulting fecal breath odor may occur. Related GI findings include anorexia, weight loss, abdominal distention, and possibly, marked malabsorption [10, 11]. A barium enema is the most reliable method of demonstrating the fistula. Barium meal showed the fistula in about 70% of the patients, whereas barium enema examination revealed the fistula in nearly all of them [11]. Although the management of GCF has historically been surgical, medical treatment is recently recommended as the first line when malignancy can be excluded. Treatment with a high dose of proton pump inhibitors (PPI) and elimination of risk factors is started. Still, when conservative treatment fails with an unresolved ulcer, a surgical approach should be considered [11]. These patients' surgical management consists of the one-stage gastrocolic resection and primary anastomosis, when possible, resection of the involved portion of the antrum and the fistula of the transverse colon with appropriate reconstruction gastrointestinal continuity [12, 13]. We present a case of gastro-colic fistula (GCF) secondary to a benign marginal ulcer complicating MGB. This is an extremely rare complication and, to our knowledge, the first reported case GCF after MGB.

Case Report

Diagnostic difficulties in gastrocolic fistulas are presented, and surgical management of this complication is discussed. We present a 42-year-old heavy smoker male who underwent laparoscopic MGB for morbid obesity two years before presenting at the emergency room. Since then, he had lost approximately 80 kg. He reported a recent weight loss of 32 kg and was finally unable to ambulate due to exhaustion. The patient suffered from chronic epigastric pain and was diagnosed with a deep MU (Figure 1).

Figure 1: Schematic view of the preoperative GI tract structure (status post one anastomosis gastric bypass). The pathology site - gastrojejunal anastomosis is circled.

Despite long treatment with high doses of proton pump inhibitors (PPIs) along with Sucralfate, the ulcer had not been resolved. The diagnostic workup should rule out the possibility of a malignant cause for the fistula. Laboratory investigations revealed hemoglobin of 9.6 g/dl, serum potassium of 2.1 mmol/L, albumin of 2.1 g/dL, along other markers of malnutrition and hypovitaminosis. UGI exams were reviewed, and a GCF was suspected. Image from the Upper Gastrointestinal (UGI) series of the patient in an upright position demonstrates the gastric pouch (GP) and the gastrojejunal anastomosis (arrow) with no evidence of leakage (Figure 2).

Figure 2: Upper Gastrointestinal series in an upright position demonstrating the gastric pouch (GP), gastrojejunal anastomosis (arrow) and the splenic flexure (SF).

An image from upper GI series obtained several minutes later shows contrast medium in the transverse colon (TC), and splenic flexure Gastroscopy revealed fecal matter in the gastric pouch, ulcer with irregular margins posterior wall of the gastrojejunal anastomosis. The fecal liquid was observed to enter through the lesion, consistent with a GCF. A fistula penetrating from the dorsal aspect of the anastomosis into the transverse colon was identified. We have emphasized to the patient the importance of smoking cessation and the high risk of developing additional marginal ulcers following bypass surgery, and why he should not resume smoking. We have also addressed the need for long-term treatment with PPIs. Given that there was a single ulcer with no evidence of gastritis or esophagitis during gastroscopy and other potential causes for ulcers were considered, such as technical factors or ischemia, we concluded that conversion to RYGB was a good option for this patient. The patient was treated preoperatively with total parenteral nutrition, and his electrolyte deficiencies were corrected.


Five trocars were used after achieving adequate pneumoperitoneum. We use a standardized trocar placement for most bariatric operations. The patient was placed in the split-leg position. After establishing a pneumoperitoneum, the intra-abdominal findings were assessed. The region of the gastrojejunostomy appeared thickened, the adhesions could not be separated using blunt dissection. The procedure started with adhesiolysis around the pouch, careful dissection, and resection of the lower part of the gastric pouch using a Harmonic Scalpel. Adhesiolysis was done with a combination of blunt, sharp, and energy devices at the region of gastrojejunostomy. During the posterior wall's adhesiolysis, a bilious fluid appeared, and the fistula was penetrating from the dorsal aspect of the anastomosis into the transverse colon uncovered. After adequate mobilization of the gastrojejunostomy, we performed en-bloc resection of the fistula and surrounding tissues; the bypassed stomach was resected. The gastroenterostomy and transverse colon were divided proximally and distally to the fistula using a linear stapler (Figures 3,4).

Figure 3: Schematic view – colon and jejunum transections were performed proximally and distally to the fistula site in the colon. Gastric remnant was resected.

Figure 4: Schematic view of the GI tract after specimen resection and retrieval.

GI tract was then reconstructed and converted to a Roux-en-Y Gastric Bypass. The transverse colon was re-anastomosed in a side-to-side fashion using Echelon linear stapler (Figure 5).

Figure 5: Schematic view - GI tract reconstruction.

The resected specimen was retrieved. The operation ended with immediate complications. Postoperatively the patient recovered well and was discharged tolerating an oral diet on postoperative day 6.


The diagnosis and definitive management of GCF are both challenging. This case report emphasizes that even a small opening between the gastrojejunal anastomosis and the colon after MGB may lead to worrisome effects and severe malnutrition. Exploratory laparoscopy with surgical en-bloc resection of the fistula and reconstruction was a safe and effective definitive surgical treatment for GCF.


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