I had diarrhea initially, but began taking Miralax within 2 months when I realized that constipation was going to be an ongoing problem. I take it daily with the doctor's blessing and I am 5 years out.
I started with stool softener a such as Ducalax and add Miralax as needed...which for me is quite often! I hope you'll be one of the lucky ones and won't need it! I do know this...Do everything you can to avoid getting impacted!!!