I'm usually okay when I use heroin but when i got clean for like 2 months on suboxone, I literally went 9 days without shitting, had to drink magnesium sulfate and then went another seven days before having to do the same thing (mind you, the magnesium sulfate was not my first option--I tried dulcolax, colace, suppositories...even the dreaded enema and none worked). The doc dropped me from 8 mg to 4mg which I think contributed to my relapse shortly after.