Colon and urology tests are clear. Organs appear normal. Doctors have no answers as to why sitting makes my abdomen hurt. Urination is painful.?

May have prostatitis. Often standard urine tests will not detect prostate infections. Prostatitis is a common cause of painful urination and lower abdominal or groin pain. Diagnosis may require seeing a urologist who treats prostatitis.
Hernia? Sitting is an activity that increases intra-abdominal pressures. If you have a hernia, it would become more symptomatic the higher the pressure.