The following causes should be considered: a. Tumor diseases, mainly colon cancer or rectal cancer, which are often accompanied by blood in the stool, diarrhea, feeling of urgency and heaviness, thinning of stool and even poor nutrition and weight loss, in addition to vague pain in the lower left abdomen. Second, adnexal diseases, such as adnexal inflammation or adnexal tumor will cause hidden pain in the left lower abdomen, and ectopic pregnancy may also occur in young women, which will also cause hidden pain in the left lower abdomen, so it is recommended that patients go to the gynecology department for consultation in a timely manner. Third, urinary stones can be manifested as hidden pain in the left lower abdomen, often accompanied by soreness and discomfort in the left lumbar region. Patients are advised to improve routine urinalysis, urinary ultrasound or CT examination to assist in the diagnosis.