Following appendix removal

Since I had my appendix removed last year, my bowel is not working properly. I have pain in my right side and a constant throbing in my back passage which is so bad at night it wakes me up.  My bladder is constantly irritated too and I am kept awake with a sore stomach.  When I go to urinate first thing in the morning, I really need to press hard to release.  It has been suggested I have diverliculitis or irritable bowl.  The pain is always there but when it flares up it is really painful. I read that after having appendix removed it can cause this and as the operation required the bowel to be stitched because the appendix was stuck to the bowel it was a particularly nasty op which could not be done with keyhole.  Can anyone help so I can go to my GP without sounding that everything isnt working - although that is just how I feel - I don't know whether it is coming from my bowel or my bladder, or whether it is both.