(I just had a hysterectomy three weeks ago, and I'm 2 years out from RNY.)  So, the pain meds (Darvocet/Tylenol) are causing me some constipation.  

I'm taking 3 colace every day,and that helps some, but not enough every day.  

So, sometimes I take a magnesium

oxide because that's what I use to balance my iron (which I'm not taking right now, because I'm already constipated enough...I'll survive a couple of weeks, and I have new lab work coming out Monday, anyway, so that will tell me where to go with the iron...) Anyway...  So, I normally run a low blood pressure (110/70 is ideal for me, but typically, I'm around 100 or 90 over 60)  This makes me a little dizzy sometimes, but it seems to be my normal.  Here's my worry: I've heard that magnesium can lower blood pressure, and after taking it, I'm dizzy even when I lie down.  Is there anything ELSE I can take for constipation that works as well?  The second problem is that I regularly (like every few days or so) get an ache that feels like it is in my colon/rectum right behind where my cervix used to be.  It feels like my plumbing is kinked and nothing can get past that spot.  Do you think it is swelling from my surgery that's pushing on my intestines?  Or, do any of the rest of you have this?  I've had it before when I was extremely constipated and pooped rocks, which is what I'm doing now, even WITH the mag oxide and colace.  Any advice?  I'm getting desparate!