Hello to All ;
I will sort of be of the subject of Miralax so I can tell you about how by Accident I bought Kellogs Fiber Plus with Antioxidants .
I bought 2 boxes that were on Sale at Costco because they were discounted $2 .
WARNINING !! you will start passing Gas after the 2nd Fiber bar . 
My stools started getting softer and I thought it was by accident .
But after the first 2 boxes were gone I went back to Costco and bought 8 more boxes and I quickly realized it was not an Accident .
WOW !! Kellogs Fiber Plus with Antioxidants really helps me . 
Now I am Hooked for life .
Now I am getting Fiber that my body needs and a lot softer Stools when I go to the Toilet .
All I can say is it works for me ,, but I still want to take 2 Exlax pills maybe 1 or 2 times a week just to help clean out anything that might not be coming out thyat should come out .
ALSO !! I would rather spend $$ on aNatural Fiber type food instead of Chemicals . 
All I can say is if you are having very Hard stools like ROCKS !! then try Kellogs Fiber Plus with Antioxidants ,, it might help .
But always keep in mind that not everything will work for everone ..