Etiology and outcome in patients with upper gastrointestinal bleeding: Study on 4747 patients in the central region of Iran.

Peptic ulcers are the most common cause of UGIB. Comorbidities, hemodynamic instability, high-risk endoscopic stigmata, history of smoking and taking NSAIDs, gastric and esophageal malignancies, may be important predisposing factors for rebleeding and mortality in patients with UGIB.