I've been on Opana 30 mg. I have a lot of trouble pooping while taking these?

These pills make my turds hard as hell, and sometimes i won't/can't go for like a week, then I have a huge toilet clogging turd. This is a serious question although it may not sound like it, but I hear constipation is common with opiates but this is crazy. I'm in a catch 22 cause if i don't take them, the pain is horrible, and when I do take them I start to get real bad stomach cramps. No answers about suboxone, withdrawals are not the problem it's side effects. Anything besides stool softeners that can help?