The Epsom salt is safe, they administer magnesium sulfate which is the same thing to prevent pre/eclampsia.
If you want, you could try a gallbladder/liver cleanse. Some have used it without issue while pregnant. Do some research though. It should be fairly safe until you get to 35/36 weeks.
Not sure what the effects will be with your essure issue though.
I know many people that have done the cleanse and they are without back pain, aches, etc and have more energy now and swear by them. Even had larger stones come out. You do need to follow the instructions just about to a t for the last days portion at least. And enemas to clear out before and after the cleanse are ok. Not later in the pregnancy, though there are some women who can't go potty unless they have one even until the day they give birth.