Magnesium sulfate / potassium sulfate / sodium sulfate
"Wish I had read these reviews first.  First time doing this.  No warning from the doctor.  It appeared to be a harmless, well-diluted clear liquid.  Casually took a drink and suddenly my mouth is full of troll urine.  Or maple syrup mixed with salty clam water.  15 minutes later and I'm waiting for it to take effect.  Strange sounds emanating from my colon.  I'm afraid."