Possible causal association between ulcerative colitis and idiopathic thrombocytopenic purpura

A 24-year-old Japanese male having ulcerative colitis and idiopathic thrombocytopenic purpura is described. When the symptoms of ulcerative colitis were manifest during his clinical course, the platelet life-span was shortened and the platelet associated IgG level was increased. Thus, causal association between the two diseases may be suggested.