OBJECTIVETo analyze the features, causes, treatments and outcomes of severe gastrointestinal (GI) bleeding after allogeneic hematopoietic stem cell transplantation (allo-HSCT).

METHODSFifteen patients suffered from massive GI bleeding (blood loss leading to hemorrhagic shock) or subacute GI bleeding (at least 1 or more units of red blood cell transfusion on each of two consecutive days) were observed and analyzed after allo-HSCT.

RESULTSSeventeen severe GI bleeding episodes occurred in 15 patients. The severe bleeding occurred in three periods of time: within 1 week, 1 to 2 months and 4 to 7 months after transplantation. The main manifestation was hematemesis and hematochezia in the first period, and hematochezia alone in the second and third periods. Platelet counts at the onset of severe bleeding were < or = 50 x 10(9)/L in the majority of patients. Causes of bleeding were conditioning regimen-related toxicity in 2 patients/episodes, graft versus host disease (GVHD) or/and intestinal cytomegalovirus (CMV) or fungal infections in 11 patients/12 episodes, intestinal CMV infections in 1 patient/episode, acid-peptic ulcer in 2 patients/episodes, and cause unknown in 1 patient/episode. Supportive care such as transfusions of platelet, red blood cell and fresh frozen plasma, H2 receptor blockers and omeprazole were given to all patients, immunosuppressive drugs to patients developed GVHD and antiviral drugs to patients with complicated CMV infection. Eight patients/9 episodes of bleeding were controlled. Eight patients continued severe GI bleeding and died of acute GVHD or related serious complications.

CONCLUSIONSSevere GI bleeding after allo-HSCT are mainly caused by regimen-related toxicity, GVHD or/and intestinal CMV infection. Bleeding caused by conditioning regimen-related toxicity is self-limited and has a better prognosis. However, treatment failure and mortality are high if the patient's bleeding resulted from GVHD and intestinal CMV infection.