Gastric Fistula

A gastric fistula is an abnormal communication between the gastric lumen and another epithelial surface or organ.

It may communicate with:

Skin, producing a gastrocutaneous fistula
Colon, producing a gastrocolic fistula
Small bowel
Pleural or thoracic cavity
Another portion of the stomach

Most clinically important postoperative fistulas evolve from a gastric staple line, anastomotic or perforation leak that fails to heal and becomes a chronic epithelialised tract.

Common settings include sleeve gastrectomy, gastrectomy, gastrojejunostomy, oesophagogastric surgery, trauma, malignancy and chronic peptic disease.

A leak is an acute transmural defect. A fistula is usually a more mature pathological communication between epithelialised surfaces.

Acute postoperative leakage may present before a mature fistula forms.

Important features include:

Persistent tachycardia
Fever
Left upper abdominal or shoulder pain
Sepsis
Purulent or gastric drain output
Enteric material from the wound
Failure to tolerate oral intake

A chronic gastrocutaneous fistula may present with persistent acidic gastric drainage through the abdominal wall, causing severe skin excoriation and fluid loss.

A gastrocolic fistula can produce diarrhoea, weight loss, malnutrition, foul eructation or faeculent vomiting.

Persistent tachycardia after upper gastrointestinal surgery should never be dismissed simply because abdominal examination is mild.

CT abdomen with oral and IV contrast: define the fistula or leak, associated collection and whether there is distal obstruction.

Upper gastrointestinal endoscopy: defines the internal opening and allows therapeutic intervention.

A contrast study may help delineate anatomy in a chronic external fistula.

Assess full blood count, renal function, electrolytes, magnesium, phosphate and nutritional status. Measure external fistula output daily.

The most important diagnostic questions are:

Is there uncontrolled sepsis?
Is there a drainable collection?
Is there distal obstruction?
Is the defect acute or chronic?
Is surrounding tissue viable?

These determine whether closure is likely to succeed.

Management begins with source control and physiological recovery, not immediate closure of the fistula.

Sepsis and collections

Keep fasting initially when an uncontrolled acute leak is present.

Drain associated collections percutaneously, endoscopically or surgically according to anatomy.

For significant postoperative gastric sepsis:

Piperacillin tazobactam 4.5 g IV every 8 hours by extended infusion, adjusted for renal function.

Use culture results to narrow therapy.

Prolonged antibiotics are not a substitute for drainage.

Give acid suppression, for example:

Pantoprazole 40 mg IV or orally every 12 hours during active high output gastric leakage.

Nutrition

Nutrition is central to fistula healing.

Use enteral feeding distal to the fistula whenever feasible, such as nasojejunal or feeding jejunostomy nutrition.

Use parenteral nutrition when enteral feeding cannot adequately meet requirements or markedly increases fistula output.

Correct magnesium, phosphate, potassium and micronutrient deficiencies aggressively.

Protect surrounding skin from acidic gastric effluent.

Endoscopic treatment

Endoscopic therapy has become central to postoperative gastric leaks and fistulas. Choice depends on defect size, chronicity, associated cavity and tissue quality.

Clips: best for small fresh defects with healthy pliable margins.

An over the scope clip provides stronger full thickness closure than standard clips and is useful for selected small fistula openings.

Endoscopic suturing: useful for larger defects when tissue can be approximated without excessive tension.

Fully covered self expanding stent: diverts luminal contents across selected acute leaks, particularly proximal gastric and oesophagogastric defects.

Stent migration is a major limitation.

Endoscopic internal drainage: useful when a contained perigastric cavity can be drained internally into the gastric lumen.

Endoscopic vacuum therapy: particularly effective for leaks associated with infected cavities. A sponge or vacuum device is positioned within the defect or cavity and exchanged serially, promoting drainage and granulation.

Chronic epithelialised fistulas are harder to close than fresh leaks because the tract has matured. De epithelialisation or tract preparation may be required before clipping or suturing.

Surgery

Operate when there is:

Generalised peritonitis
Haemodynamic instability
Uncontrolled sepsis despite drainage
Gastric necrosis
Large uncontained disruption
Distal mechanical obstruction preventing healing
Failed appropriate endoscopic therapy
Chronic fistula with anatomy unsuitable for minimally invasive closure

Definitive surgery may require fistula tract excision, gastric resection, revision of the original anastomosis or reconstruction.

Do not perform repeated closure attempts without correcting distal obstruction, uncontrolled infection or severe malnutrition. These are major reasons fistulas fail to heal.

Clinical toolsCalculators

BMI GCS EDD Parkland Formula

Corrected Sodium Corrected Calcium Anion Gap Creatinine Clearance Insulin Calculations qSOFA Wells PE Wells DVT CHA₂DS₂-VASc HAS-BLED CURB-65 Centor/McIsaac

Intussusception

Intussusception is telescoping of a proximal bowel segment into an adjacent distal segment, dragging its mesentery with it. Progressive venous congestion can cause bowel oedema, obstruction, arterial compromise, infarction and perforation.

Adult intussusception differs fundamentally from paediatric disease. In adults, a structural lead point is common and may be benign or malignant. Colonic intussusception carries a particularly high malignancy risk. A 2025 systematic review found malignancy in approximately 68% of colocolic and 46% of ileocolic cases, compared with about 9% of enteric small bowel cases.

Transient short segment enteroenteric intussusceptions are increasingly detected incidentally on CT and do not all require surgery.

Adults may present acutely with bowel obstruction or with intermittent symptoms over days to weeks.

Typical features are colicky abdominal pain, nausea, vomiting and distension. Gastrointestinal bleeding or a palpable mass may occur but the classic paediatric triad of pain, bloody stool and abdominal mass is uncommon in adults.

Continuous pain, focal guarding, fever, tachycardia or peritonism suggests bowel ischaemia or perforation.

An intermittent presentation with recurrent obstructive symptoms should raise suspicion for a mobile intussusception around a persistent lead point such as tumour, polyp, Meckel diverticulum or benign small bowel lesion.

CT abdomen and pelvis with IV contrast: diagnostic investigation of choice in adults; demonstrates bowel within bowel configuration and determines whether there is obstruction, a structural lead point or compromised bowel.

Check full blood count, renal function and electrolytes in obstructed patients. Add lactate and blood gas where bowel ischaemia is suspected. A normal lactate does not exclude early vascular compromise.

Colonoscopy may be useful in selected stable colonic presentations when obstruction is incomplete and malignancy needs evaluation, but should not delay surgery for threatened bowel.

Management depends on location, symptoms, lead point and bowel viability.

Immediate surgery is required for peritonitis, perforation, bowel ischaemia, complete obstruction or clinical deterioration.

Adult colonic intussusception should usually undergo oncological segmental resection without attempted reduction when malignancy is possible. Reduction risks perforation of oedematous bowel and theoretical tumour dissemination.

Small bowel intussusception is more nuanced. If the bowel is viable and imaging or operative findings suggest a benign lead point, gentle reduction can be attempted to preserve bowel length. Resect the lead point bearing segment after successful reduction. If reduction fails, bowel is compromised or malignancy is suspected, perform en bloc resection.

A short, incidental enteroenteric intussusception without obstruction, lead point or symptoms may be observed with clinical follow up rather than automatically operated upon. Recent evidence suggests short segments below approximately 3.5 cm without a lead point are particularly likely to be transient, although this threshold should support rather than replace clinical judgement.

In children, management is different. Pneumatic or hydrostatic enema reduction is first line for uncomplicated ileocolic intussusception. Peritonitis, perforation, shock, failed reduction or a pathological lead point requiring treatment mandates surgery.

Gastric Fistula

Overview

Clinical Features

Diagnosis

Management

Overview

Clinical Features

Diagnosis

Management