I know exactly how you feel. Please take a look around forum for older posts. There are 4-5 recent (in last 6 months) posts on here where people have found cures for themselves. You may want to try their regimes, you never know it may help.
Also there is info on CureZone about hemmoroids (there are internal ones you can't see), food allergies , TMAU, and other possible reasons for this. Lots of people think it has to do with Candida, Leaky gut, IBS,or sluggish livers. I hope you narrow it down for yourself. Good luck on your search. May we all find a cure.