I haven't had any intestinal issues with Medifast, but my guts are very easygoing - nothing bothers them. I started taking a fiber supplement when I started, because I heard that constipation was a more likely problem, and Medifast contains less fiber than I was previously consuming.
Maybe a little extra fiber would help "soak up" the extra liquid in your system??
I remember reading this on some medifast board (might have been the actual medifast board). It’s not uncommon to have a bowel movement every 2-3 days, particularly on a full fast. If you become constipated, Metamucil tabs or a daily Metamucil drink (or other fiber powder that dissolves into a drink) will set everything right again.
Yes, I tend to have the opposite problem also, but I have read that if you are eating the bars, they do have Maltitol in them and that can cause loose bowels in sensitive folks.
week one down
I started taking a fiber supplement when I started, because I heard that constipation was a more likely problem, and Medifast contains less fiber than I was previously consuming. 
