I was prescribed Prepopik as a bowel-preparation solution for a colonoscopy. I followed instructions, as per both my physician's direction and as written on the box, even setting a timer to be assured I stirred the contents of the package(s) 2-3 minutes, as directed. I had no affect whatsoever (not even gas!), and I ingested the second packet 6 hours later (as per instruction), at which time I still had no bowel movement. Finally, almost 8 hours later, I had a bowel movement, which was relatively small and not at all watery. I went to bed, woke at 5:30 a.m., for my 6:00 a.m. appointment, and still nothing. No cramping, grumbling or gas to indicate anything was even possibly going to happen! I considered calling the medical center to cancel the appointment, but my husband suggested we proceed and see if there might be a way to salvage the appointment. My doctor was incredibly surprised I did not have success with this product, but he decided to 'mildly sedate' me and attempt the colonoscopy, even though I had no result from taking Prepopik, because I had eaten lightly for days before leading up to the procedure, and I had regular bowel movements, daily, prior to. We were hopeful I was 'clean enough' to proceed with the scope. My doctor stopped the procedure minutes after starting (due to not being able to perform the scope) , and I was rescheduled. About 28 hours after taking my first dose, I experienced stomach cramping, a 'side stitch' under my rib, horrible distention of my abdomen (which lasted about 3 hours) and, finally(!), the urge to have a bowel movement; when I attempted a movement, I felt constipated! I would recommend the product only due to the minimal amount of solution I had to drink versus the volume of other horrific solutions I had to drink for prior scopes, and the fact that the taste was not horrible. I was quite bummed (pun intended!) it didn't work for me and will seek a full refund ($39) from the manufacturer. Read More Read Less