Patients with a short bowel have usually had a bowel resection for Crohn's disease. Two types of short-bowel patient can be distinguished: those with a jejunostomy and those with their jejunum anastomosed to a functioning colon. Both types of patient have problems with macronutrient absorption, although those with a colon experience fewer problems because some energy from unabsorbed carbohydrate is salvaged in the colon. Patients with a jejunostomy have problems with large stomal losses of water, sodium and magnesium, whereas those with a jejuno-colic anastomosis rarely have problems with water and electrolyte absorption. Patients with a jejunostomy 100-200 cm from the duodeno-jejunal flexure ('absorbers') usually absorb more from the diet than they pass through the stoma and therefore require oral electrolyte or nutrient supplements. Those with a residual jejunal length of less than 100 cm usually secrete more from the stoma than they take in orally ('secretors') and therefore require long-term parenteral fluid or nutrient supplements. A high output resulting from a jejunostomy is treated by reducing the oral intake of hypotonic fluid, administering a sipped glucose-saline solution and, often, by giving drugs that reduce intestinal motility (most effective in absorbers) or gastrointestinal secretions (most effective in secretors). Gallstones are common both in short-bowel patients with and in those without a colon (45%), and calcium oxalate renal stones occur in the former (25%). However, it is now possible to provide adequate nutrition and fluid supplements for most patients with a short bowel, and the prospects for the rehabilitation of such patients are good.