Short Bowel Syndrome

Short bowel syndrome is the clinical consequence of insufficient functional small bowel following extensive resection or loss of absorptive function.

ESPEN defines anatomical short bowel syndrome in adults as a residual small bowel length below 200 cm in continuity. Functional short bowel syndrome can occur with a longer intestine when absorptive function is severely impaired.

Anatomy strongly determines severity:

• Type 1: end jejunostomy
• Type 2: jejunum connected to colon
• Type 3: jejunum connected to residual ileum with colon and ileocaecal valve preserved

An end jejunostomy has the greatest fluid and sodium loss. Preservation of ileum and colon markedly improves fluid, electrolyte and energy salvage.

High output diarrhoea or stoma losses dominate early disease.

Patients develop thirst, dehydration, oliguria, sodium depletion, hypomagnesaemia, weight loss and malnutrition.

Terminal ileal loss predisposes to vitamin B12 deficiency and bile salt malabsorption. Loss of significant ileum and colon changes oxalate handling and increases renal stone risk.

Patients with colon in continuity can develop D lactate neurological syndromes from fermentation of malabsorbed carbohydrate.

Gastric hypersecretion is most significant during the early months after major small bowel resection and can further increase intestinal output.

Document residual small bowel length from the duodenojejunal flexure, remaining ileum, ileocaecal valve and percentage of colon in continuity.

Measure daily oral intake, stool or stoma output and urine volume.

Renal function, sodium, potassium, magnesium and bicarbonate require close monitoring early. Long term surveillance includes vitamin B12, folate, iron, calcium, phosphate, magnesium, vitamin D and other micronutrients according to anatomy and dependence on parenteral support.

The diagnosis of intestinal failure is established when intravenous fluids or nutrition are required to maintain health.

Management has three goals: maintain hydration and nutrition, promote intestinal adaptation and progressively reduce parenteral support when possible.

Enteral exposure should be introduced and increased as tolerated because luminal nutrients stimulate adaptation.

Patients with a colon in continuity generally benefit from complex carbohydrate rich diets because the colon can salvage carbohydrate through fermentation to short chain fatty acids.

In high output jejunostomy, indiscriminate drinking of plain water can increase net sodium and water loss. Restrict excessive hypotonic fluids such as water, tea and coffee and hypertonic drinks such as fruit juice and soft drinks. Use a high sodium glucose oral rehydration solution, generally containing approximately 90 to 120 mmol/L sodium, sipped through the day.

Add salt liberally in patients with high jejunostomy losses.

For high output:

Loperamide 4 mg orally three to four times daily, preferably 30 to 60 minutes before meals and at bedtime, is first line. Some short bowel patients require doses above conventional licensed limits because enterohepatic recycling is impaired, but high dose therapy should be titrated by an intestinal failure specialist because excessive loperamide exposure can cause serious cardiac toxicity. ESPEN prefers loperamide to codeine because it lacks sedation and dependence.

Gastric antisecretory therapy is particularly useful during the first months after major resection and when output exceeds approximately 2 L per day.

A practical regimen is:

Omeprazole 20 to 40 mg orally once or twice daily, titrated according to output and absorptive anatomy.

Parenteral fluid or nutrition is required when oral and enteral therapy cannot maintain urine output, electrolytes, nutritional state or body weight. Home parenteral nutrition is appropriate for chronic intestinal failure.

Where anatomy permits, restore intestinal continuity and bring excluded colon or ileum back into circuit. Surgical reconstruction can substantially reduce long term parenteral requirements.

For selected adults with stable short bowel associated intestinal failure who remain dependent on parenteral support despite optimised conventional treatment, teduglutide 0.05 mg/kg subcutaneously once daily can increase intestinal absorption and reduce parenteral fluid or nutrition requirements. Treatment should be managed by an experienced intestinal failure centre with objective monitoring of fluid and nutritional requirements.

Teduglutide can increase fluid absorption rapidly, so parenteral fluid requirements may need reduction to avoid fluid overload. Patients require appropriate gastrointestinal neoplasia screening and monitoring according to the product protocol.

Long term surveillance should actively address catheter infection, central venous thrombosis, renal dysfunction, nephrolithiasis, gallstones, metabolic bone disease, micronutrient deficiency and intestinal failure associated liver disease.

The practical endpoint is intestinal autonomy, meaning maintenance of hydration and nutrition without intravenous supplementation.