I've been in pain management for about a year and a half on a pretty high dose of meds. My biggest side effect/issue I've had being on narcotic medication is the constipation. Constantly bloated, can never go, straining with very little success, stomach as far as it can go to the point where I'm in pain, never feeling empty, etc. It's been incredibly frustrating to say the least. I've tried all the OTC laxatives but no substantial improvements. I couldn't go even the tinest bit without taking up to 12 laxatives and 2 suppositores up my butt (sorry) ...and even that...wasn't much to write home about. Alas! I have found something that provides substantial relief...and it's natural!  Magnesium Oxide. You can go to Walgreens and find it. I get the 200 tablet bottles made by Nature's Bounty (green bottle). Each tablet is 500mg. I have found that taking 5-6 tablets (2500-3000mg) before I go to bed works great for me. In Pain Management, Magnesium is said to be benificial. Some doctors charge $200 for high dose Magnesium injections. I only bring that up to say that taking 5 or 6 tablets is safe. There are a few different kinds of Magnesium you will run in to, I have found Magnesium OXIDE to work the best. In the morning, I will have to run to the bathroom a few times because the uh, 'reward' is spread out. Sometimes even throughout the day I'll have to go a little bit. But honestly, I MUCH rather have that issue than giving myself intense 3 day headaches from straining so hard . I have found the 5-6 range works for me, if that's too much/little for you than you can adjust your dosage accordingly. I haven't taken laxatives for almost 2 months...that's amazing considering I couldn't go without them.   Hope this helps!