There are many causes of left tummy pain, the most common ones are the following: 1. urinary stones, if patients have urinary stones, they will have left tummy cramps, the pain often spreads to the perineum, some patients will feel soreness in the left lumbar region, it is recommended that patients have routine urine examination, ultrasound or CT examination of the urinary system. 2. colorectal tumors, including colon cancer and rectal cancer, usually have hidden pain in the left tummy, sometimes accompanied by diarrhea, often with blood in the stool and a feeling of urgency, or even thinning of the stool. 3. Sometimes it is accompanied by diarrhea, often with blood in the stool, a feeling of urgency and heaviness, and even thin stool, suggesting patients to improve tumor marker examination and colonoscopy for clear diagnosis. 3. Female patients with stomach pain may be suffering from adnexal diseases, such as adnexal inflammation, adnexal tumor, ectopic pregnancy, etc. It is suggested that patients should seek medical treatment from gynecology department in time to clarify the cause and then perform corresponding treatment.