After reading through this whole post I have to call bullshit on a few things. To summarize my experience a bit, I have been on and off every opiate pain killer there is for chronic back pain, I've had three back surgeries. At the peak of my pain, before the last surgery, I was taking enough oxy to kill half a stable of horses. 3-60mg oxycontin and four to six 15mg oxycodone a day, everyday. First of all, anyone who says that Miralax (or any Polyethylene Glycol, PG) doesn't work for them, they didn't use it properly. PG's are osmotic-type laxatives, they're very different from any stimulant laxative or bulk forming fiber laxative. PG does NOT work overnight like stimulant laxatives do. If you're already to the point of having impacted bowels, (150 shit nuggets packed just inside your bunghole) no laxative will work effectively. You have to start when your bowel is relatively clear. So, after you are able to have a bowel movement and feel relatively free, then start using PG, use it everyday, use a few double doses to start off with. It's by far the safest, least harmful laxative there is. It won't churn your guts up and make you have GI gas and pain at all. All PG does is draw water into your bowels and intestines hence why it's called an osmotic-type laxative. Drawing water in will naturally soften those rock hard shit nuggets. It also allows your body to produce the mucous you normally have in your bowel which is the natural lube that slides out a turd.
The bleeding in your stool is happening because the inside of your bowel and poop chute is as dry as the Sahara, then shove 100 dry, crusty nuggets through there and it causes small abrasions on the inside of your bowel that bleed. That is a very normal occurrence for anyone that has had to learn the hard way about severe opiate constipation.
Now the real nasty part!

I don't know about your level of comfort with having strangers jammin their fingers up your ass to relieve an impacted bowel, I simply won't go to the hospital for that. I would literally die of embarrassment cause I know what's in there! You can relieve your own impacted bowel without anyone's help, all by your lonesome in the bathroom, door closed, and nobody will be the wiser. But you will need a strong stomach and a sink or something near by to wash your hand off as you're doing it. The first few nuggets are the hardest to get out because they've been packed together so tightly, but ya just break it apart with the point of your finger and hook it with the same finger and pull. Then repeat.. You'll eventually break up the ball of nuggets enough that the rest will slide out like normal.. I had to do this a bunch of times before my sister the Dr. made me drink Miralax regularly. After I learned how to use PG, I never had another serious problem. If you're not to the point of an impacted bowel yet, you can probably start using PG and in 2-5 days, VIOLA! Then just drink a glass of PG in water every few days and enjoy regularity again!
I'm happy to note that I've been off of pain killers completely since Feb, 2014.
Those are the realities of cronic opiate constipation. Almost everyone experiences the same things at some point if they are prolonged users of opiates.
Hope that helps clear the fodder a bit!