Hello, it depends on the cause of his bleeding. Rebleeding after initial improvement usually involves ulcers or esophageal varices. There are effective treatments for both conditions. A gastroenterologist treats them endoscopically. Hemorrhagic gastritis (another potential cause of upper gastrointestinal bleeding) usually stops even without treatment within a few hours and heals within 24 hours. If you do know which of the above conditions is the cause, I ll be able to give you more specific information. I hope I ve helped! Kind Regards!