Magnesium hydroxide
"I was constipated for about 5 days do to taking diet pills. I took MOM at about 1030pm at night I woke up at about 5 am rubbing my belly and thinking I can't believe this stuff hasn't kicked in. When I tell you that thought hadn't even left my mind yet it kicked in and with a bang!!!! I barely made it to the bathroom. I felt so much better even though I almost pooped on myself!!!!"