Bariatric surgery complications


  • Roux-en-Y - malabsorptive and restrictive physiology;
  • Gastric Sleeve - restrictive
  • Biliopancreatic diversion
  • Vertical banded gastroplasty - now historical as replaced by LAP band;
  • Lap Band Complications
Gastric sleeve
Biliopancreatic diversion
Lap band

Clinical Features

Differential Diagnosis



  • Upper GI bleed
    • Resuscitate in standard fashion
    • Emergent endoscopy
    • Often bleed from staple lines, ulcers
  • Anastomotic Leak or Stricture
    • Progressive inability to tolerate PO
    • Abdominal pain
    • Solids first then liquids
    • Needs UGI then likely endoscopy
  • Marginal Ulcer
  • Internal hernia
    • Obstructive or nonobstructive
    • Crampy, intermittent abdominal pain radiating to back
    • Can have normal abdominal exam
    • May strangulate herniated bowel
    • Work up with CT Abdomen/pelvis and UGI
    • CT findings: swirl sign, intussuscepted bowel
    • Needs surgery early
  • Nutritional Complications


  • CT AP - use PO & IV contrast
    • patients often cannot tolerate full 1L of PO contrast
    • sip as much contrast as possible in 3hrs then CT
    • weight limit of CT scanner often exceeded
    • can use Gastrografin UGI series instead
  • UGI series
    • beware GI pouch limits on contrast volume
    • useful for perforation, internal hernia, stricture, leak

Specific Surgeries

Roux-en-Y gastric bypass

  • Creation of a small gastric pouch and an anastomosis to the jejunum
  • Gastric remnant distention[1]
    • Remnant is a blind pouch that may become distended with paralytic ileus
    • Potential rupture → severe peritonitis
    • 3.9% leak rate for RYGB; overall mortality 0.6%
    • Jejunojejunostomy leak associated with 40% mortality
    • Signs/symptoms: pain, hiccups, LUQ tympany, shoulder pain, abdominal distention
    • Diagnosis: XR shows large gastric air bubble vs CT
    • Treatment: emergent operative decompression with percutaneous drainage
  • Stomal Stenosis
    • Occurs in 6-20% of RYGB patients
    • Possibly related to tissue ischemia or tension on GJ anastomosis
    • Presentation several weeks after surgery
    • Signs/symptoms: nausea/vomiting, dysphagia, GERD, inability to tolerate PO
    • Diagnose with endoscopy vs UGI series vs CT
  • Marginal Ulcers
    • Occur in 0.6-16% of RYGB patients
    • Acid injury to jejunum
    • Causes: poor perfusion 2/2 tension/ischemia, increase gastric acid exposure, NSAID use, H pylori infection
    • Signs/symptoms: Nausea, pain, bleeding +/- perforation
    • Diagnose with endoscopy
    • Patients typically medically managed
  • Cholelithiasis
    • 38% of RYGB patients
      • Risk reduced to 2% if ursodiol given as post-op ppx
      • Some surgeons perform prophylactic cholecystectomy with RYB procedure
    • Rapid weight loss increases lithogenicity of bile
    • Diagnosis: U/S or MRCP
  • Hernias
    • Ventral hernias (0-1.8% in lap RYGB)
    • Internal hernias (0-5%)
      • Intermittent and may be difficult to detect via CT
      • Suspected may require urgent surgical exploration lest patient has strangulated pathology
  • Dumping Syndrome
    • Occur in up to 50% of patients when high levels of carbohydrates are ingested
    • Early dumping syndrome
      • Occurs when pylorus is either removed or bypassed, allowing hyperosmolar stomach chyme to "dump" into the small intestine.
      • Hyperosmolality of food → fluid shifts into GI lumen → colicky and abdominal pain, diarrhea, nausea, tachycardia, diaphoresis, dizziness, syncope.
      • Treatment: Diet modification to avoid high simple sugars
    • Late dumping syndrome

Gastric Banding

  • Placement of restrictive ring over the gastric cardia near the GE junction
  • Lowest mortality rate among all bariatric surgeries (0.05% mortality)
  • Stomal Obstruction
    • Early complication; occurs in 14% go GB patients
    • Typically due to inclusion over excess perigastric fat vs tissue edema vs inappropriate sized band
    • Signs/symptoms: nausea/vomiting inability to tolerate PO
    • Diagnosis: UGI series vs CT
    • If due to edema, may be treated with NG tube decompression until swelling improves
      • May require surgical revision if above unsuccessful
  • Port infection
    • 0.3-9% of GB patients
    • associated with band erosion
    • treatment: Replacement of port if isolated infection vs band if more extensive
  • Band Erosion
    • Up to 7% of GB patients
    • Erodes through gastric wall secondary to wall ischemia vs mechanical stress from band
    • Occurs on average 22 months after surgery
    • signs/symptoms: evidence of infection, failure to lose weight, nausea/vomiting, epigastric pain and hematemesis
    • Diagnosis: Endoscopy vs CT
    • Treatment: Band removal
  • Band Slippage/gastric prolapse
    • 2-14% of patients
    • Either anterior or posterior prolapse
    • Signs/Symptoms: Food intolerance, epigastric pain, acid reflux
    • Diagnosis: Upper GI series vs CT
    • Treatment: Emergent surgery
  • Esophageal dilatation
    • Up to 10% of patients
    • associated with over-inflated bands or excessive food intake
    • Signs/symptoms: Food/saliva intolerance, reflux, epigastric pain
    • Diagnosis: UGI series vs CT
    • Treatment: Fluid removal from band initially and behavioral modifications
  • Hiatus hernia
    • Results in refractory reflux

Sleeve gastrectomy

  • Creates sleeve out of the stomach and removes portion of greater curvature of stomach
  • Complication rate 3-24%; mortality 0.39%
  • Bleeding
    • Typically occur from the staple line
  • Stenosis
    • Can lead to gastric outlet obstruction
    • Signs/symptoms: Dysphagia, vomiting, dehydration, inability to tolerate PO
    • Dx: UGI series vs CT
    • treatment: Endoscopic dilatation vs surgical intervention depending on involvement
  • Gastric leaks
    • Up to 5.3% of patients; most serious complication associated with sleeve gastrectomy
    • 2/2 poor healing in setting of inadequate blood supply vs weakness at staple line vs gastric-wall heat ischemia from cautery
    • Treatment: surgical repair vs percutaneous drainage/antibiotic/NPO
  • Reflux
    • Common post-op complication
    • Treated medically initially with eventual RYGB for refractory cases

See Also

External Links


  1. Tack, Jan, et al. “Complications of bariatric surgery: Dumping syndrome, reflux and vitamin deficiencies.” Best practice and research clinical gastroenterology; 28; 2014; pages 741-749.
  1. Lee S, Carmody B, Wolfe L, Demaria E, Kellum JM, Sugerman H, Maher JW. Effect of location and speed of diagnosis on anastomotic leak outcomes in 3828 gastric bypass cases. J Gastrointest Surg. 2007;11(6):708.