//I once tried taurine but it gave me bright green poop for some days//
What do you suppose the bright green was? It's bilirubin. You were expelling liquid bile. Or your transit time was too fast for it to darken from bacterial action.
How long did you stay with the taurine?
Since it's such a long term problem you would have to stay with it for quite a while, and adjust the dosage along the way. The adjustment period will be challenging and you probably have a lot of other issues too since the system was down for so long. You should go back on taurine and try some fiber binders or cholestryamine.