I Am 57 And Never Had Constipation, How Ever In

I am 57 and never had constipation, how ever in last 6 weeks I have been very plugged, so much so I don't feel like eating. I have over the last 6 months had symptoms of enlarged prostrate, if I stand and pee it comes out normal, but sitting I have week steam and little comes out. I don't understand being constipated as I never have been befor, could they be related?