Linaclotide
"You have to find what works best for you with Linzess and when you do, you will LOVE this drug.  I've had irritable bowel with severe constipation for all my adult life.  My insurance does not cover this drug yet I am willing to pay for it.  I have lost weight and no longer feel bloated all the time.  Before Linzess, Miralax was the only thing that even barely worked (after a few days).  Another commenter is right, if you take it more than 1/2 hour before eating (I wake up and take it in the wee hours of the morning or as soon as I wake up.)  The earlier you take it, the more the bowel movement will contain a lot of water as well.  A cup of coffee in the morning can jumpstart it."