Magnesium Citrate

 How long does the effects of this stuff last?????

What effects are you talking about, how much magnesium are you taking, and why are you taking it?

 10oz.  To prepare for surgery tomorrow. I'm wondering how long it will continue to do its job......

For me I took it at 8 am Saturday and was still going at 7 am Monday.took about 6 hours from when I took it to start working

It lasted until allllllll of my "stuff" was gone. I took it at like 8 pm the night before surgery and I didn't start "going" until the morning. I know that I still felt the need to go when I was registering for surgery and it was all out by about 12 but I still felt the need to go even while I was in the operating room. Thankfully the stuff had done it's job and there was nothing left.

If anything, take it earlier rather than later.  You'll be cleaned out either way, but you won't be feeling the urgency.  Your thirst will be taken care of as soon as they give you a line. My first bag during preop was wide open and I felt no thirst once I was hooked up.  Good luck.