question: Hello - my 11 year old was seen at the ER about a month ago for severe abdominal pain.  We thought he was having appendicitis, and it turns out that he was very backed up in the intestines with stool.  He is a distance runner and runs about 20-30 miles per week.  He is 4'9 inches and weighs 77 pounds.  We have been giving him a daily dose of miralax and recently the pediatrician upped it to 1 and 1/2 cap full per day.  He has increased his water intake, but still could drink more (in this mom's opinion!).He is not having the acute belly pain any longer, but does get sharp stabbing pains before and sometimes after a BM.  The BM is now flaky.  I was wondering if I should be taking him for a follow up x-ray to see if he has decreased the amount of stool in there.  What do you think?