病历摘要患者男性,89岁。于2005年9月17日中午无诱因自觉下腹隐痛,有便意,排便后站立时突然出现晕厥,面色苍白,双手发凉,无四肢抽搐,迅速坐回便器上休息,约20 min后自行恢复神志,后解出约50 ml稀便。卧床后呕吐数口胃内容物,无血性或咖啡色样物,测血压130／70 mm Hg,心率 Patient summary Male patient, 89 years old. At noon on September 17, 2005 no incentive to consciously abdominal pain, there is a sign, stool suddenly appeared after defecation, pale, hands cool, no limbs convulsions, quickly sit on the toilet to rest, about 20 minutes to restore their consciousness , After about 50 ml of loose stool solution. Vomiting in bed after a few mouthfuls of stomach contents, no bloody or brown samples, measuring blood pressure 130/70 mm Hg, heart rate