Concerned mum, and Jessica, My son is three and is always thirsty as well. I've never let him go to bed without a pullup on because he always has to go to the restroom. And I too am sceptical about taking away liquids. TJ also has sickle cell and that alone makes him very thirsty. dehydration is more of a fear for me because I know he'll grow out of the bed wetting. just to be sure though, you should ask your ped.