Does Miralax still work of its drank through out the day instead of all at once?

I have been taking Miralax for a while now. I'm not a doctor but I do know my own body and I find the more water I drink at once the better the Miralax works. I am prescribed 3 caps a day I take them all at once and I drink the water right down with it and right behind it. If I mix 3 caps with a bottle of water 16.9 Oz bottles then I'll drink two bottles right after. Tell your son I know how he feels I'm not that thirsty either but it works quicker for me and my problems. Even if he continues to take one cap in the a.m. and one cap in the p.m. it will help to drink it all at once. As I have read up on Miralax and have seen it on TV commercials it pulls the water from your body. Again I am not a doctor and I'm not sure exactly why your son takes it but have him try all at once and it wouldn't hurt to drink some extra water right after good luck