We present a 42 yo AAM with pmhx of recently diagnosed hereditary hemochromatosis and GERD, with complaints of abdominal pain and chronic diarrhea. He reported a 1.5 year history of loose, watery stools, which occur three times daily, denied rectal bleeding, fever or weight loss. Physical exam was unremarkable. Stool studies including ova and parasites, culture, fecal leukocytes and clostridium difficile were negative. Anti-transglutaminase and anti-endomysial antibodies, ESR, CRP and TSH were also negative. Colonoscopy revealed erythematous mucosa in the transverse colon and rectum; biopsies from the terminal ileum and each section of the colon revealed non-caseating microgranulomas that stained negative for acid-fast bacilli and fungi. EGD revealed diffuse erythema, erosions and duodenitis with non-caseating microgranulomas in the stomach and duodenum and H.pylori negative. CT of the abdomen and pelvis showed hepatosplenomegaly, however, recent liver biopsy did not show granulomas. CT enterography showed normal small bowel. CT Chest was unremarkable. Angiotensin converting enzyme was elevated. ANA, quantiferon gold, RPR, Tropheryma whippelii PCR, and Histoplasma antigen were negative. With a high suspicion for sarcoidosis, he was referred to rheumatology. He was lost to follow up, then returned two years later with abdominal pain and diarrhea, up to 15 episodes daily. The patient had a repeat EGD and colonoscopy, which again revealed non-caseating granulomas from the stomach to the left colon. Stains for Whipple's disease and mycobacterium were negative. Prednisone 40 mg daily was started for likely GI sarcoidosis. Within three weeks, the patient reported his abdominal pain and diarrhea had resolved. Sarcoidosis is a granulomatous disorder that affects multiple organ systems and is characterized by noncaseating granulomas. GI sarcoidosis is an extremely rare entity of the disease and symptomatic involvement is even less frequent. When the GI tract is involved, the stomach is the most common site and the small intestine is the least common form of GI involvement. Colonic sarcoidosis has been reported in fewer than 20 cases. In addition to biopsies demonstrating non-caseating granulomas and no AFB or fungi, rapid improvement with corticosteroid therapy is supportive of the diagnosis. Diagnosing GI sarcoidosis is difficult, it is important to rule out other differential causes of granulomatous disease such as infection with mycobacterium, syphilis, Crohn's disease, fungal infections, foreign body or idiopathic granulomatous reaction, prior to initiating therapy. The patient responded favorably to corticosteroid therapy, which highly supports the diagnosis of sarcoidosis. Our case is unique since the involvement of sarcoidosis was present throughout the GI tract (stomach, small intestine, and colon).Figure 1