constipation
"My experience is only a week old, and I'm here to see what other users have diarrhea during the initial two weeks of taking Linzess.  But I did want to reply to Bronx boy's fears about what will help him if this doesn't.  Magnesium.  I deeply understand his fear, as there's nothing worse than constipation.  Before Linzess, I took a product called CALM, which is a fizzy drink of magnesium citrate.  IT WORKS!  My problem with it is it woke me up in the night - works fast.  I've found, during these initial days of taking Linzess, that I can still take CALM in the morning if I have that miserable "incomplete" feeling, and CALM will work within an hour on an empty stomach.  I rated it at 5 at this point pending further experience."