Gastrointestinal fistulas (GIFs) arise as a complication of the surgical treatment of a number of malignant and non-malignant diseases. Fluid loss and electrolyte and nutritional imbalance are related to increased morbidity and mortality in these patients. A multidisciplinary approach under the leadership of the surgeon is essential for successful therapy. Because complication rates are higher in malnourished patients with fistulas, enteral or total parenteral nutritional (TPN) support should be initiated after the patient has been stabilized with respect to fluid loss, acid-base, and sepsis. Pharmacotherapy with somatostatin and octreotide has been shown to reduce fistula output and shorten closure time.