Short Bowel Syndrome

Key Features

• Malabsorptive condition following removal of significant portions of the small intestine

• Causes

  • Crohn disease

  • Mesenteric infarction

  • Radiation enteritis

  • Volvulus

  • Tumor resection

  • Trauma

• Type and degree of malabsorption depend on length and site of resection and degree of adaptation of remaining bowel

Clinical Findings

• Terminal ileal resection

  • Watery diarrhea

  • Malabsorption of bile salts and vitamin B₁₂

  • Low serum vitamin B₁₂ levels

  • Steatorrhea and malabsorption of fat-soluble vitamins

  • Cholesterol gallstones

  • Calcium oxalate kidney stones

• Extensive (> 40–50%) small bowel resection: short bowel syndrome, characterized by weight loss and diarrhea due to nutrient, water, and electrolyte malabsorption

Diagnosis

• Clinical diagnosis based on presence of diarrhea and malabsorption with prior bowel resection

Treatment

Terminal ileal resection

• Vitamin B₁₂ injections subcutaneously or intramuscularly monthly

• If watery diarrhea, bile salt-binding resins with meals (cholestyramine, 2–4 g/day orally, colestipol tablets 1–2 g orally once or twice daily, or colesevelam, 625 mg, 1–3 tablets orally twice daily)

• Cholestyramine or colestipol doses can be slowly increased (cholestyramine maximum 24 mg/day; colestipol tablets 16 g/day), but the higher doses are associated with increased side effects of nausea, bloating, and constipation

• Calcium supplements to bind oxalate

Extensive small bowel resection

• If the colon is preserved, 100 cm of proximal jejunum may be sufficient to maintain adequate oral nutrition with a low-fat, high–complex-carbohydrate diet

• If the colon has been removed, at least 200 cm of proximal jejunum is typically required to maintain oral nutrition

• Parenteral vitamin supplementation

• Monitor levels of zinc, selenium, and magnesium

• Antidiarrheal agents (eg, loperamide, 2–4 mg three times daily orally)

• Octreotide

• Proton pump inhibitor to reduce acid hypersecretion

• Total parenteral nutrition (TPN) required if < 100–200 cm of proximal jejunum intact

• TPN has an estimated annual mortality rate of 2–5% resulting from TPN-induced liver disease, sepsis, loss of venous access

• Teduglutide

  • Stimulates small bowel growth and absorption

  • Has resulted in a reduced need for parenteral nutrition

• Small intestinal transplantation, chiefly for patients in whom severe problems develop from TPN