I have had similar experiences of gushing diarrhea during first 1.5- 2 month of using Linzess 290 mcg. I would have the runs in the morning but feel great for the reminder of the day. Since I started bottle number three I feel like i am taking a sugar pill, meaning there is no effect at all. I had to go back to taking two dose of Miralax a day on the top of Linzess to produce a bowel movement. I bought my Linzess at Walgreen's so i did not think that the pills had a chance to be tempered with. The bottle had the safety seal on it. Did any one noticed similar effects?