The causes of abdominal pain include overactive bladder, urinary stones, urinary tract infection, bladder polyps or tumors. 1. Overactive bladder syndrome: it can be manifested as urinary urgency, frequent urination, pain in the lower abdomen after holding urine, etc. When urinating, bladder spasm can occur, and when it is serious, it can cause pain in the lower abdomen. 2. Urinary stones: such as urethral stones, bladder stones, etc., when urinating, the stones can be in the bladder with the urine activity, the bladder mucosa irritation, thus appearing the symptoms of abdominal pain, but also with urinary urgency, urinary pain, hematuria and other symptoms. 3. Inflammation of the urinary system: such as acute and chronic cystitis, mostly related to bacterial infections, can also be secondary to kidney infections, there can be urinary pain, urinary urgency, urinary urgency and other symptoms when urinating, due to inflammation stimulation can cause pain in the abdomen, and in severe cases, hematuria can occur. 4. Bladder polyps, tumors: If the bladder polyps or tumors are large in size, causing damage to the bladder mucosa, there may be symptoms of abdominal pain when urinating, mostly accompanied by obvious hematuria. If the symptoms of pain in the abdomen when urinating occur, it is recommended to consult a doctor in time, complete the examination, clarify the cause of the disease and then actively treat it, so as not to delay the condition.