患者，男，75岁。于1999-12－23来我院就诊。既往健康，近两年懒动、纳差，很少吃蔬菜。临床表现头痛、烦渴，腹泻便秘交替发生，时有脓血便，里急后重。症状进行性加重，坐、立位即有大便，童少，卧位时症状可缓解．体格消瘦、腹胀、痛苦面容。临床检查下腹部们及6cm×2.5cm大 Patient, male, 75 years old. In 1999-12-23 to our hospital. Past health, the past two years lazy, anorexia, rarely eat vegetables. Clinical manifestations of headache, polydipsia, diarrhea, alternating constipation, when there is pus and blood, tenesmus. Symptoms progressive increase, sitting, standing position that stool, children less, lying position when the symptoms can be alleviated. Physical weight loss, bloating, painful face. Clinical examination of the abdomen and 6cm × 2.5cm large