Hello,
Thank you for your query at DoctorSpring.com
I understand your concern.
It is possible that you may be suffering from cystitis, which means that the bladder is inflamed, and each time when you pass stool through your colon, it puts pressure on the bladder, making you urinate immediately after you have a BM.
I will advise you to follow up with me after a CT KUB.
Regards.