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 should be administered one to three times daily with meals

  • Cholestyramine, 2–4 g/day orally

  • Colestipol tablets, 2 g orally

  • Colesevelam, 625 mg orally

• Unabsorbed fatty acids bind with calcium, reducing its absorption and enhancing the absorption of oxalate

• Administer calcium supplements to bind oxalate

• If steatorrhea, institute a low-fat diet supplemented with medium-chain triglycerides and vitamins

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

• Administer vitamin supplementation parenterally

• Monitor levels of folate, iron, calcium, zinc, selenium, and magnesium

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

• Octreotide (50–1500 mcg/day subcutaneously or intravenously in two to three times daily doses beginning at 50 mcg and increasing by a 100-mcg dose every 48 h)

• Addition of a proton pump inhibitor can help reduce acid hypersecretion

• Total parenteral nutrition (TPN) may be required if < 100–200 cm of proximal jejunum is 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 can be considered, chiefly for patients in whom severe problems develop from TPN