you need to do it when you feel the urge, your bowel should start relaxing 5 seconds after gasping for air feeling. You need to exhale 70% of air, and than start holding your breath. Try it couple times when you feel high urge, for me it works I don't lie, I dont see any reason why I should lie, I just want to help others deal with that hell and when I've discovered that this method works on me I've decided to share it with others. keep trying and let me know if anyone succeed.

<sorry for my english :<

P.S you can read more about breath holding technique on the forum for shy bladder syndrome www.paruresis.org First I've cured my shy bladder syndrome and than I've noticed that it also works for shy bowel, even better for #2.