My 101 Old Husband Has An Obsession With BMs And

My 101 old husband has an obsession with BMs and takes everything under the sun for constipation. t the same time he does not drink the three tall glasses of water recommended and sometimes reuses to eat. Nothing in, nothing out. He does not underststand this and goes literally berserk if he does not have a BM. I understand that Mganesium Citrate liquid is like motoroil on the intestines and can be dangerous. Your take on this, please. R.K.