Short gut syndrome

Question 1

Pathophysiology

Answer 1

1. When lose 50-70% loss of small bowel, or when total length loss of functioning bowel below the minimal required for digestion and absorption
2. Loss of bowel= less absorptive capacity->carbs less affected->bile acids absorbed in ileum= -ve absorption of fats, ADEK, steatorrhea
3. Impaired absorption of vitamin B12
4. Fluid loss
5. Adaptation occurs in first 6 months: cell hyperplasia, deepening of intestinal crypts, ++enzymes, lengthening of villous

Question 2

Why is it important to start enteral feeds as soon as tolerated

Answer 2

Improves adaptation

Question 3

Outcome determinants

Answer 3

1. Site->jejunum better tolerated
2. Extent of resection
3. Younger->better adaptation
4. Intact ileocolic valve->less colonisation of ileum from colon
5. Better if stomach and colon intact
6. Health of residual bowel

Question 4

Etiology in adults and children

Answer 4

1. Adults
Crohns
Mesenteric infarction
Radiation enteritis
Volvulus
2. Children
Congenital, volvulus
Necrotising enterocolitis

Question 5

Types of procedures

Answer 5

1. Jejunal resection w/ intact ileum and colon
2. Jejunum-colon= jejuno-ileal resection
3. Jejunostomy (jejunum, ileum, colon)

Question 6

Acute management

Answer 6

1. Oral diet: ORS when thirsty, +++calories, complex carbohydrates, starch/soluble, low oxalate, lactose. If bile salt malabsorption->medium chain triacylglycerides.
2. Rehydration: dextrose + 1/2 N saline then additions, must dilute as hyperosmolar
3. Loperamide/codeine
4. Calcium
5. Parenteral support with weaning
6. Pantoprazole, octreotide
7. Electrolyte, vitamin, micronutrient replacement
8. Monthly vitamine 12 injection
9. Glutamine to inhibit bacterial overgrowth

Question 7

Long-term management

Answer 7

1. Regular nutritional assessment
2. Monitoring fluids/electrolytes
3. Ready available ORS when ills
4. Calorie and protein intake adequate
5. MCTG supps
6. Oral/enteral whenever possible
7. Replace vit B12, Ca, vit D, mg, zinc,
   folate
8. Anti-diarrheals, Octreotide, cholestyramine

Question 8

Effects of jejuno-ileal resection

Answer 8

1. Gradual weight loss
2. Water/electrolytes depleted
3. Malabsorption
4. Lactic acidosis
5. Oxalate renal calculi->+reabsorption of oxalate in large bowel
6. Pigmented stones
7. Adaptation
8. Diarrhea

Question 9

Investigations

Answer 9

1. FBC-> anemia
2. UEC-> variable
3. Albumin-> low
4. Mg, Calcium, zinc, selenium, folate
5. Vitamins-> low
6. INR increased

Tests to consider

1. LFTs->may be abnormal in TPN
2. Urine-> N, proteinuria in nephrotic, hematuria in neprholithiasis
3. Fecal fat->fat malabsorption
4. Upper GI contrast series->shortened intestinal length
5. DXA->osteopenia, osteoporosis
6. Abdominal USS->gall stones
7. CT abdomen-> kidney stones

Question 10

Surgical options

Answer 10

lengthening of the intestine, implantation of artificial intestinal valves, and the use of reversed intestinal segments or a recirculating loop.

Question 11

Role of colon, disadvantages

Answer 11

1. short-chain fatty acid absorption
2. fluid reabsorption
3. delay in intestinal transit time.

Disadvantages of the colon in these patients
1. absorption of oxalate leading to increased risk of calcium oxalate kidney stones,
2. patients with their colons in continuity are prone to the development of secretory diarrhea from bile acid exposure to the colonic
mucosa.