Intestinal failure and short bowel syndrome

Intestinal failure is usefully defined as a reduction of intestinal function such that ordinary fluids and nutrients given by mouth are insufficient, and that at least partial artificial support by the parenteral route is needed to maintain health. Intestinal failure usually follows major resection (e.g. in short bowel syndrome [SBS]), but also occurs when the intact intestine is unable to function owing to inflammation or disorders of motility. In many patients, both causes co-exist. Chronic intestinal failure is relatively rare, with a prevalence of 2–4 per 100,000 and an incidence of 2–4 per 1,000,000. Adaptation occurs in the first months after injury and comprises hyperplasia and hypertrophy; this is potentially responsive to trophic factors. In SBS, intestinal volume losses may exceed 5 L per day. The biggest challenge in SBS management is preventing consumption of spontaneous excess fluid orally, as this is generally sodium-free and drives intestinal secretion. Initial therapeutic steps include intravenous sodium, reduced oral intake of hypotonic fluid, increased sodium intake and high-energy foods. Formula feeds should be polymeric with additional sodium and magnesium. Useful drugs include loperamide, codeine and proton pump inhibitors. Somatostatin agents are not especially helpful, but glucagon-related peptides may become important. Parenteral nutrition should be avoided, if possible, but when essential, follows a routine format. The risk–benefit equation is beginning to favour intestinal transplantation in selected patients, and complete failure of intravenous nutrition should no longer be awaited.