A woman with epigastric pain, vomiting, weight loss, and an upper gastrointestinal series showing antral rigidity suggestive of linitis plastica was found to have granulomatous inflammation of the stomach. Additional investigations disclosed more extensive gastrointestinal involvement, with noncaseating granulomas found in esophageal and colonic mucosa, despite normal appearances at endoscopy. Intestinal permeability to [51Cr]EDTA was increased, suggesting intestinal mucosal injury. No specific entity, including disseminated sarcoidosis or Crohn's disease, was diagnosed. This patient with granulomatous gastroenteritis had a clinical and histologic response to medical therapy with prednisone and recurrence of symptoms when prednisone was tapered. Her clinical course was similar to that of previous cases of idiopathic isolated granulomatous gastritis treated nonsurgically. Cases of idiopathic isolated granulomatous gastritis should be categorized as such only if a thorough evaluation has been performed to determine extent of disease, as well as to exclude other entities.