We report the case of a 7-yr-old girl with Turner syndrome, ulcerative colitis (UC) and coarctation of the aorta. The diagnosis of Turner syndrome was made in early infancy (karyotype analysis 45, X). Growth hormone treatment was started at 3 yr and 2 mo of age. From the age of 4 yr and 5 mo, the patient suffered from persistent diarrhea with traces of blood and intermittent abdominal discomfort. As these symptoms gradually deteriorated, she was referred to our clinic at the age of 7 yr for further evaluation. Barium enema showed aphtha and loss of the fine network pattern in the descending colon and rectum. An endoscopic examination showed ulceration, edema, friability, and erythema beginning in the rectum and extending up to the splenic flexure of the descending colon. The histology of the descending colon area showed severe stromal infiltration of inflammatory cells. These endoscopic findings and the histological findings were consistent with UC. Thus, based on these findings, the patient was diagnosed as having UC. Mesalazine therapy was initiated at this time. The patient is currently being treated with mesalazine (1,000 mg/day) and abdominal symptoms and bloody diarrhea have disappeared. GH therapy was not interrupted during the therapy for UC. Retrospectively, growth hormone improved growth velocity (9 cm/year) during the first year of treatment, however from the age of 4 yr, growth velocity decreased (4–5 cm/yr) in spite of the GH treatment. Conclusion: Patients with Turner syndrome and gastrointestinal symptoms should be investigated for inflammatory bowel diseases. Growth velocity is useful for evaluating the presence of inflammatory bowel diseases and other systemic diseases.