Below the navel is the small abdomen of human body, and the organs in the small abdomen can be classified as follows according to different systems: 1. digestive system, including ileum, sigmoid colon and rectum, among which the junction of rectum and b is the site of malignant tumor, once the tumor causes intestinal obstruction, radical surgery for sigmoid colon cancer is needed to remove the tumor and relieve intestinal obstruction. 2. urinary organs, including bladder and the entrance of ureter on both sides, patients with urinary tract infection often have stones or tumors in the bladder. Patients with urinary tract infection often have stones or tumors in the bladder, and at the same time, they will have urinary tract infection symptoms such as urinary urgency, urinary frequency and urinary pain. atrophy.