magnesium citrate

hi everyone.:) I use magnesium citrate(the same stuff used in bowel prep for a colonoscopy) when I'm suffering from constipation(usually as a last resort) but I've heard it's dangerous to take and should only be used for the colonoscopy prep,is this true? it works really well for me,without any cramping unlike a lot of other remedies.I'm having a really bad spell(miralax isn't working.) and I think I need to flush out my whole system. is this drug safe?
thank you so much!

Also keep in mind that I believe that when we hear of these dangers, they almost always pertain to times a person is on a restricted diet, performing a bowel prep for surgery or a procedure. In other words, you're not eating solids, your liquids are limited, you're already depleted of nutrients. I've never been so desperate for normalcy to take Cit Mag or the Fleet's Phospho Soda but I've been tempted. I have done Fleet's saline enema's many times though BUT each time I do one I make sure I go into it all fully hyrated, I've eaten a healthy meal prior and I continue eating/drinking. Sipping tall glass of water, eating saltines, etc.

thanks for all your comments guys.:) I didn't have to take it thank God. but i just wanted to know for sure because I have had to use it before,and I've been worried that it was really harsh. anyway,hope your all doing well and thanks again for your responses.:)

Renne, glad things improved.