The following diseases may be present: 1. Cystitis or urethritis, which can appear as congestion and edema of the mucosa of the urethra and bladder, accompanied by surface erosion and other changes, can appear as pain in the small abdomen when urinating, which can be accompanied by frequent urination, urinary urgency and pain in the urethra, accompanied by a feeling of incomplete urination, etc. Serious patients may also appear hematuria. It is recommended to perform routine urine examination and urine culture examination, as well as urological ultrasound to further confirm the diagnosis.2. Bladder stones or posterior urethral stones may cause pain in the abdomen when urinating, which may be related to the irritation of the local mucosa by stones, accompanied by symptoms such as urinary frequency and urinary urgency. Ultrasound examination of the urinary system is recommended to confirm the diagnosis of stones. 3. Tumors and polyps in the bladder can cause pain in the abdomen when urinating, mostly due to hematuria, which requires CT examination of the urinary system to further confirm the diagnosis of tumors or polyps in the bladder.