Gastrointestinal bleeding (GIB) is an emergency medical situation that is very common, although often benign but can cause considerable morbidity and mortality and health care costs. The aim of this study was to analyze the endoscopic evaluation of upper GIB (UGIB) and lower GIB (LGIB) in Sistan and Balouchestan, southeast Iran.

Data from patients with GIB in a referral university-affiliated hospital in Zahedan, Southeastern Iran during a 10-year period, were obtained. A total of 21 884 reports of adult patients’ endoscopy and colonoscopy from 2011 to 2020 who were admitted to Ali-Ibn-Abitaleb hospital were studied of which 5862 reports were related to GIB. Incomplete files were excluded. Information on age, sex, and endoscopic diagnosis of the 5053 reports was analyzed and compared using chi-square statistical test.

There were 3310 men (65.6%) and 1743 women (34.4%) with a mean (± SD) of age 48.4 (± 19.83) years. 3079 patients had UGIB (60.8%) and 1974 patients had LGIB (39.2%). Peptic ulcer (72.8% duodenal ulcer and 27.2% gastric ulcer) was seen as the main reason for UGIB (29.7%) and hemorrhoids were the main reason for LGIB (44.2%). Mallory–Weiss syndrome was significantly common in the age < 40 years old, and the incidence rate of malignancy was significantly higher in those aged > 40 years old than in the younger age group (P < 0.001).

Peptic ulcer was the most common etiological factor and it was more common in men than in women. Gastroesophageal varices were the second most common cause of UGIB. Hemorrhoids and anal fissures were observed as the most common colonoscopic findings of LGIB. The prevalences of UGIB and LGIB are more common in men than women and increase with age. It is important for physicians to constantly update their information about the spectrum of diseases in their region and their changing over time to provide accurate diagnosis and management timely.