There are many diseases that can cause pain in the left lower abdomen, such as chronic pelvic inflammatory disease, chronic tubal inflammation, uterine fibroids, ovarian cysts, sigmoid colon tumors or descending colon tumors, rectal tumors, ureteral stones, etc. If it is a left ovarian cyst, a general gynecological ultrasound examination can reveal a cystic mass on the ovary, and after a clear diagnosis, laparoscopic cyst debridement surgery is usually performed. If it is chronic pelvic inflammatory disease or chronic tubal inflammatory disease, anti-infection treatment is needed, such as oral cefixime and intravenous cefoxitin if necessary. If the pain is caused by colon tumor, it is usually accompanied by changes in bowel habits and frequency, such as thinning of stool, thinning of stool, or even blood in the stool, which can be further clarified by colonoscopy if necessary.