The mother of a 5 year old boy with all the symptoms of functional constipation was correctly told by her child's pediatrician to start him on Miralax but incorrectly told to stop the Miralax after only 2 weeks. As expected, while taking the Miralax his stool softened and he started to have BMs more frequently, but he quickly regressed when the Miralax was stopped.
Based on the pediatrician's initial recommendation, this mother understandably thought that the laxative should only be given for two weeks then stopped. Not surprisingly when she contacted me she was stuck in a unsuccessful "start-stop-start" Miralax routine.
In an earlier post I explained how stopping laxatives too soon is one of the two most common mistakes made by parents and pediatricians. And as I discuss in my book, laxatives must be continued long enough for a child to stop withholding and for the child's rectum to shrink back to its normal size. This can take anywhere from 6-12 months or longer in some children. The longer a child has had functional constipation, the longer it will take for the rectum to shrink back.
I know this seems like a long time, but there is, unfortunately, no quick fix for functional constipation or encopresis.