Hugs to you. I'm so sorry you aren't feeling well. I have similar symptosm to yours so I thought I would post. I myself have endometriosis. Did they ever diagnose or check for this? The pain you described in your rectal area sounds very similar to what I had experienced. My pain came on very intense and then I would end up with the diarhhea, which was torture to pass, even as diarhhhea. I figured that was God's way of sparing me having to pass a hard stool. I ended up having laser surgery and I had a large amount of endo in my cul de sac. Apparently this is one of the most painful areas to have it. I have to say the surgery has helped it's going on about a year now. BUT now I have the pain that you described....the pain with turning in bed at night. Now that I am convinced is adhesions. I say this with confidence because it stems from my left ovary up into my rib area. I had severe adhesions which were removed with the laser surgery last April. Well now they are back and much more intense. The only thing that I find helps is Yoga. It doesn't take the pain away completely but I can sleep much better at night. I have to do it every night or I tighten right back up. Now it doesn't hurt to do the Yoga but it's a little uncomfortable but feels good at the same time. You would have to try it to know what I am talking about. I hope this helps you. You may have tried this already. I wish you all the best and I hope you find some relief from pain soon. I know how devasting this can be on ones life.
God bless you, Mary