39 yo male. pain in the lower left quadrant of abdomen for 2 years. ct scan unremarkable except shows bladder wall thickening. could this be cause?

Bladder wall: Bladder wall thickening may be an indication of lower urinary tract obstruction. May need further evaluation or maybe unrelated.

Depends: Focal bladder wall thickening or inflammation is not normal. If the bladder is not full, the wall will frequently look mildly diffusely thickened which is a normal finding. You should have your doctor review this with the radiologist.