患者 ,男 ,4 5岁 ,因“解暗红色血便 1ｄ”入院。患者 1ｄ前无明显诱因下解暗红色血便。入院当日下午出现腹痛后又解暗红色血便 ,量约 110 0ｍｌ,伴头晕 ,心悸等症状 ,急诊入院。体检 :体温 37.5℃ ,脉搏 90次 /ｍｉｎ ,呼吸 2 2次 /ｍｉｎ ,血压 90 / 6 0ｍｍＨｇ(1ｍｍＨｇ = Patient, male, 45 years old, admitted to hospital for “solution of dark red bloody stool 1d.” Patients without obvious incentive to dissolve dark red bloody stool 1d ago. In the afternoon on the day of admission, he developed abdominal pain and dissolved dark red bloody stools. The amount was about 110ml, accompanied by symptoms of dizziness and palpitations, and emergency admission. Physical examination: body temperature 37.5 ℃, pulse 90 beats / min, breath 2 2 beats / min, blood pressure 90/60 mmHg (1mmHg =