Hi, After going through your boyfriend s case for blood in vomiting there might be following possibilities - 1) Gastritis with erosion or repeated vomitting. 2) Deranged coagulation due to infection. I want to know- 1) Any rashes over body. 2) Bleeding from any other sites like nasal bleed or black colored stool or patichie over skin. 3) Associated symptoms like cough, cold, breathing difficulties. 4) Habits like smoking, alcohol. I would advise him to- 1) Do complete blood count (low hemoglobin level and low platelet count gives clue for cause of bleeding), kidney and liver function tests including coagulation profile. 2) Chest xray, ultrasonography of abdomen may be helpfull. 3) Endoscopy may be needed.