Unusual causes of gastrocolic fistula.

1. Three cases of gastrocolic fistula of unusual cause are presented. These include one patient each with carcinoma of the left kidney, gastric lymphoma, and granulomatous colitis. 2. The relationships between the kidneys and gastrointestinal tract are illustrated by a cadaveric cross-section. 3. The wide variety of diseases resulting in gastrocolic fistula is discussed. 4. Careful fluoroscopic and radiographic study may be necessary to detect the site of the fistula and to identify its cause.