1. Etiology

• most problems occur if >25% of the 200-300 cm of small bowel is removed (or <90-100 cm left)
• long-term prognosis depends on the amount, and which section, of small bowel is removed:
  • loss of the distal small bowel is more serious than loss of the proximal small bowel
  • resection of proximal small bowel:
    • massive malabsorption of water, electrolytes, fat, protein, carbohydrates, vitamins, minerals
    • transient problem with significant improvement in months as the distal small bowel can compensate
  • resection of distal small bowel (ileum):
    • bile acid & vit. B12 malabsorption -> malabsorption
    • resection of ileocecal valve -> Stagnant Loop Syndrome
    • increased gastrin secretion -> gastric hypersecretion -> peptic acid disease -> ulcers & malabsorption
    • no improvement in bile acid or vit B12 absorption as proximal bowel cannot compensate

1. Gastrointestinal Manifestations

1. For Malabsorption

• see file on "Malabsorptive Disorders"

2. Serum

• hypogammaglobulinemia, hypocomplementemia, hypomagnesemia, hypocalcemia, and hyperoxaluria

1. Phase 1

• TPN for excessive stool volume loss via a central line
• goals:
  • nutritional replacement
  • stabilized fluid and electrolyte balance
  • vitamin and mineral supplementation
• gradual weaning off of TPN with introduction of enteral feeds

2. Phase 2

• gradual introduction of elemental enteral nutrition:
  • continuous and isotonic fluids
  • via NG or gastrostomy tube
  • medium-chain triglycerides for severe steatorrhea
  • dietary glucose or fructose better than disaccharides
• gradual increase in enteral nutritional volume if:
  • stool - pH > 5.5 and no reducing substances
  • not an excessive stool output
• enteral nutrition is necessary to stimulate an increase in mucosal mass and thus increase the absorptive capacity of the remaining bowel

3. Phase 3

• gradual introduction to bolus enteral or solid feedings
• vitamin and mineral supplementation:
  • Vitamin B12 supplements if a large portion of ileum resected
  • Vitamin D supplements to prevent rickets
  • Vitamin K supplements if increased PT
• others:
  • cholestyramine which bind bile salts to decrease diarrhea
  • antacids to prevent gastric hyperacidity
  • oral antibiotics to prevent bacterial overgrowth
  • loperamide hydrochloride to prevent gastric hypermotility

4. Surgery

• liver/small intestinal transplants are experimental