The pain in the stomach after urination may be caused by urinary tract infection, overactive bladder syndrome, bladder stones, etc., and the cause should be promptly identified in the hospital. 1. Urinary system infection: due to urethral infection with Escherichia coli, streptococcus, staphylococcus aureus, etc., resulting in local mucosal damage, leading to significant pain in the urine, after urination, the lower abdomen is uncomfortable. 2. Overactive bladder syndrome: due to the bladder and urethra muscle group contraction dysfunction, resulting in a transient spasmodic contraction pain in the lower abdomen after urination. 3. Bladder stones: due to urinary tract obstruction, infection, bladder foreign body and other causes, pain after urination, hematuria and other symptoms. There may be other reasons for the pain in the abdomen after urination, it is recommended to actively seek medical attention, under the guidance of a professional physician.