I Have Duchenne Muscular Dystrophy , I Am 17 And

I have Duchenne muscular dystrophy , I am 17 and I am a male. I have been having some issues when I go to the bathroom. I was constipated I think but took some ex-lax . It seemed to work but now it feels like I have to go all the time. Yesterday my urine has been almost black with a red tint to it. I've been drinking a lot of water. It lightens up a little but goes back to very dark. Plus it feels like my bladder hurts when I see. What should I do.