Pain in the lower left side of the small stomach, there are several common cases: 1, left colon, rectal lesions: such as inflammatory diseases, ulcerative colitis, ulcerative colitis lesions, if concentrated in the rectum above, such as the sigmoid colon and the descending colon in this part of the time, there will be pain in the left lower abdomen, accompanied by mucus, pus and blood stools, a day may be solved 3-4 times of the mucus, pus and blood stools. In addition, neoplastic lesions in the left half of the colon, or polyps, diverticulitis, etc. can also cause left lower abdominal pain, such as diverticulitis of the sigmoid colon, adenomas of the rectum, sigmoid colon, descending colon or rectal cancer, sigmoid colon carcinoma, descending colon carcinoma and other diseases, which may require surgical treatment; 2. Left small intestinal lesion: Inflammatory lesions of the small intestine, such as Crohn’s disease, intestinal tuberculosis, and there is a functional lesion, such as intestinal dysfunction, etc.; 3, Left ureteral stone: in addition to intestinal lesions, left lower abdominal pain may also have systemic diseases, such as left ureteral stone, etc.; 4, bladder, prostate, seminal vesicle glands: if there is inflammation, tumors can also cause pain in the left lower abdomen; 5, the left side of the ovaries, fallopian tubes, the uterus: if there is inflammation, tumors can also cause pain in the left lower abdomen.