BACKGROUND: The aim of this study was to investigate the efficacy of capsule endoscopy (CE) performed on patients who presented to emergency room with clinically evident gastrointestinal (GI) bleeding from unknown source and were hospitalized for follow-up.METHODS: Total of 38 patients who underwent CE and were followed-up for evaluation of clinically perceptible GI bleeding with no obvious etiology in Istanbul Medical Faculty emergency surgery department were included in the study. Patient data, which were collected between January 1, 2007 and June 1, 2015, were reviewed retrospectively.RESULTS: Of the 38 patients included in this study, 12 (32%) patients were women and 26 (68%) were men. Average age was 55.57 years (range: 20-88 years). Nine patients were using anticoagulants. Ten patients were followed-up in intensive care, and 7 patients underwent angiography. Angioembolization was performed for 1 patient who was diagnosed as having active bleed with CE. Average erythrocyte suspension replacement was 20.7 units. Total of 13 patients underwent surgery for bleeding found with CE. Eleven (34%) patients underwent double-balloon endoscopy, during which 5 patients were treated with cauterization and sclerotherapy was performed on 2. Four (18%) patients died during the study period: 2 died as result of bleeding from unknown source, 1 died of cholangiocarcinoma recurrence, and 1 died of anastomotic leakage. One patient was readmitted to hospital due to recurrence of bleeding. Nineteen (50%) patients were treated successfully based on CE findings. Diagnostic yield of CE was determined to be 78.9%. Average length of hospital stay was 32.68 days (range: 3-153 days).CONCLUSION: CE is an effective tool to detect source of GI bleeding. CE should be first choice of evaluation method for patients admitted to emergency room with obscure overt GI bleeding once radiological imaging determines absence of obstruction.