Drug therapy and nutritional management of patients with gastrointestinal fistulas.

The drug therapy and nutritional management of patients with gastrointestinal fistulas are reviewed. The goal of therapy is to compensate for loss of electrolytes, nutrients, and water in the fistula drainage and to monitor the acid-base status of the patient. Positive nitrogen balance is essential for anabolism and closure of the fistula. Usually it is not feasible to analyze the fistula drainage for nitrogen content, and nitrogen requirements must be estimated. To prevent folic acid deficiencies, patients should receive daily doses of folic acid 1 mg orally or 0.5 mg in parenteral nutrient solutions. Positive zinc balance usually can be established with the addition to parenteral nutrient solutions of zinc 3-12 mg/day. It is not clear whether the parenteral or enteral route of nutrient administration is preferable. Drug therapy may be needed to treat diarrhea, infection, and any underlying disease. Reductions in the acidity and the volume of fluid lost may allow spontaneous closure and healing; antacids and anticholinergic drugs are not recommended for these purposes. The use of cimetidine has been effective in decreasing the acid content and volume of output from fistulas in the upper gastrointestinal tract and has allowed spontaneous healing to occur. Drainage of any intra-abdominal abscesses is essential; this should be combined with systemic antibiotic therapy. The management of patients with gastrointestinal fistulas is complex because of disturbances in fluid, electrolyte, and acid-base balance and because of difficulties in determining nutritional requirements.