Abdominal pain after urination may be caused by cystitis, bladder stones, bladder tumors, overactive bladder syndrome and other diseases. 1. Cystitis: It is usually related to factors such as bad habits and pathogen infection. After the patient urinates, it will cause irritation to the diseased area of the bladder, causing pain in the lower abdomen. 2. Bladder stones: usually caused by dietary factors, age factors. After the patient urinates, the stone stimulates the mucous membrane will cause damage to the mucous membrane and painful symptoms. 3. Bladder tumor: usually caused by lifestyle, environmental factors, pathogen infection and other factors. After the patient urinates, the urine may cause irritation to the bladder tumor, causing pain in the lower abdomen. 4. Overactive bladder syndrome: Overactive bladder syndrome may also cause abdominal pain after urination. There may be other reasons for patients to have pain in the abdomen after urinating.