Table 1. Risk, Prevention, and Treatment of Postoperative Gastrointestinal and Nutritional Complications in Bariatric Patients

Complication	Risk by Procedure			Prevention	Treatment
	LAGB	RYGB	BPD and DS
Nutritional
Vitamin deficiency
Iron	0	++	++	Multivitamin with iron and vitamin C	Ferrous sulfate 300 mg/d with vitamin C
Vitamin B12	0	++	+	1,000 μg/mo IM or 300-500 μg/d orally or nasal spray 500 μg/wk	1,000 μg/mo IM or 300-500 μg/d orally or 500 μg/wk nasal spray
Folic acid	0	++	++	Folate 1 mg/d usually in multivitamin	Folate 1 mg/d
Fat-soluble vitamins A, D, E, K	0	+	++	Multivitamin, including at least 400 IU vitamin D	Replace vitamin as indicated
Thiamine	0	+	++	Multivitamin with thiamine	50 mg IV
Mineral deficiency
Calcium	0	+	++	1,500 mg/d elemental calcium	1,500 mg/d elemental calcium
Insufficient weight loss	+	0	0	Obesity support group; dietary education	Consider alternative bariatric operation
Excessive weight loss	0	+	++	Dietary education; appropriate surgery	Conduct dietary education; consider surgical revision
Hepatobiliary
Gallstones and sludge	+	++	++	Ursodeoxycholic acid 300 mg twice daily for 6 mo; consider elective cholecystectomy	Conduct cholecystectomy
Luminal
Stomal ulceration	0	+	+	Avoid NSAIDs; consider prophylactic PPI (pouch must not be too large)	Stop NSAIDs; prescribe PPI; conduct surgical revision
Stomal stenosis	0	+	+	Surgical technique; prevent ulcers; avoid silastic band	Conduct endoscopic dilation; remove silastic band; conduct surgical revision
Band erosion	+	0	0	Surgical technique	Conduct surgical revision
Staple line dehiscence	0	+	0	Surgical technique	Conduct surgical revision
Fistula	0	+	+	Surgical technique; prevent ulcers	Treat endoscopically; consider surgical revision
Internal hernia	0	+	+	Surgical technique	Treat as surgical emergency
Bile reflux	0	+	0	Roux limb must be long enough; rule out obstruction.	Conduct surgical revision
GI tract bleeding	0	+	+	Avoid NSAIDs	Treat endoscopically; prescribe PPI
Dumping syndrome	0	+	+	Small meals; dietary education	Conduct dietary education; consider surgical reversal (rarely)
GERD	+	0	0	Choose correct procedure	Prescribe PPI; conduct surgical revision
Functional
Vomiting	++	+	+	Small meals; prevent ulceration and stenosis	Dilate stenosis endoscopically; conduct surgical revision; conduct dietary education
Diarrhea	0	+	++	Appropriate diet	Treat infection; rule out bacterial overgrowth; administer loperamide; consider surgical revision
Bloating and flatulence	0	+	++	Consider small-bowel bacterial overgrowth	Exclude and treat bacterial overgrowth; conduct dietary education

BPD = biliopancreatic diversion; DS = duodenal switch; GERD = gastroesophageal reflux disease; GI = gastrointestinal; IM = intramuscular; IU = international units; IV = intravenous; LAGB = laparoscopic adjustable gastric band; NSAIDs = nonsteroidal anti-inflammatory drugs; PPI = proton pump inhibitor; RYGB = Roux-en-Y gastric bypass.
0, rare; +, occasional; ++, frequent.