Nonfuntioning intestinal tract

I'm interested to know if anyone else has this issue and what the treatment is. I'll try to keep it short. I've had chronic constipation all my life (I'm 28 now). When I was 2 I was diagnosed with anal/rectal strictures. I was put on laxatives, not sure what kind. I think those stopped working and I was put on Senekot from as early as I can remember, age 6ish. I was taking Senekot from then until I had a colostomy when I was 22. I know long term use of laxatives can damage the intestines. Since my surgery, my constipation has been coming back. I can go weeks/months without having any output. The last few months I've tried everything I can think of to get things moving with no result. I'm miserable, look pregnant, in pain. I was also recently diagnosed with a condition that includes nerve disorders. My neuro thinks my intestinal issues might be a result of that. I've taken colonoscopy preps with no BM after. The worst one included the golytely, 2 bottles mag citrate, bottle of lactolose, and 4 dulcolax, all in one day and did nothing! I'm starting to think my intestines just don't function, maybe from the years of taking the stimulant lax Senekot? Is there anyone else with this issue? I see my neurologist and GI next week so I will definitely bring it up again.