Is it normal to have pain while urinating after an appendectomy?

My 4 year old son just has his appendix removed one week ago. I had ruptured but the dr said just a little bit. He seemed to get well really quick (Thank God!). However, he has started saying his pee pee hurts. At first it was while the was going now it hurts when he isn't. Is this normal? Dr also said the appendix was touching his bladder. Could his bladder just be inflamed or is it something more serious?