患者男 ,2 0岁 ,因反复便血 7年 ,再发加重 5ｄ ,于 2 0 0 0年 5月 30日入院。每次便血量大 ,呈暗红色 ,有血凝块 ,无腹痛、呕吐 ,经止血、输血、对症及支持等治疗可停止。曾于1997年因便血在缅甸医院行剖腹探查术 ,未能明确病因 ,行结肠镜检查亦未发现异常。入院前 5ｄ无诱因? The patient male, 20 years old, was hospitalized on May 30, 2000 because of repeated bloody stools for 7 years, and he suffered an increase of 5 days. Each time he had large blood volume, dark red, blood clots, no abdominal pain, and vomiting. Hemostasis, blood transfusions, symptomatic and supportive treatments could stop. In 1997, he had undergone a laparotomy at a Burmese hospital because of blood in the stool. He had not been able to determine the cause of the disease and his colonoscopy did not reveal any abnormalities. 5d no incentive before admission?