Case presentation: A 32-year-old man with dyspepsia and rectorrhagia dating back 3 weeks underwent endoscopy and colonoscopy. Upper GI endoscopy revealed a 2×2cm submucosal lesion at the gastric body. Endoscopic ultrasonography confirmed GIST and surgery was recommended. Colonoscopy diagnosed left side inflammatory bowel disease (IBD) (ulcerative colitis). Abdominal CT scan and sonography had no apparent abnormality. The pathology report confirmed low grade, spindle type gastrointestinal stromal tumor (GIST). Treatment was started with oral Mesalazine and Asacol enema. As the abdominal and pelvic CT showed no metastasis, a complete surgical resection of the tumor was performed and in a 6-month follow up, the patient had no problem.
Discussion: IBD patients are at an increased risk of malignancy due to chronic inflammatory state and the use of immunomodulator agents. Thus, the risk of malignancies at the beginning of the disease is low and its occurrence is rare.  The most common cancer in such patients is adenocarcinoma and GIST is somehow rare, with a small number reported in literature. Since the presence of GIST is not related to disease activity, it should be considered in differential diagnosis in patients with controlled IBD who are still symptomatic.