I seem to remember some people reporting "constipation" during the Miracle-Mineral-Supplement , but it appears to be very unusual occurrence. Most likely you are going to hit the opposite end of the scale, the "diarrhea".
That's one of the favorite parts of this process for me, to just see all that gunk leaving my body... and my body FEELS so much CLEANER.
I can assure you, if you stay with the protocol long enough (and that is a big IF, since it does seem a bit tedious at times, and seems tempting to just "fugghet about it" and quit), so if you stick with it long enough, you will experience massive de-worming and detoxifying in lot of different ways.