I too have suffered from both issues. I was able to get over, and mostly control, the IBS though. Because it is anxiety related I just had to think and concentrate on relaxing when I was in situations that triggered anxiety. Also when I have time I will flush out my colon as best I can by drinking water and eating raw fruits. Of course this will only be for short vacations from work and school, but it definitely helps to have no waste built up in your system for the anxiety to trigger the IBS symptoms.
But now, parcopresis controls my life, although I have made steps in trying to overcome it- I have told a few people and currently live in a dorm. I am able to have a bowel movement but feel as though I'm not going enough when I do. I believe this is the case because I often have lots of bad gas throughout the day.
Sorry I may not have been much help but just know we are all suffering through these things together.