Six year old just had a white bowel movement before bed

So my son is six and before bed tonight he had to go poop. While he was pooping he locked the door so i tols him to unlock it and the went to inspect if he really was pooping. Sure enough, he was but i am concerned about the coloring. I dont usually look at his poop because he is six and can manage.It smelled like regular poop, it looked like your typical turd, only thing different is that it was white in color, 100% except for the tip of one turd was a real light brown.The past few days he has had a stomach ache, which everyone gets and deals with so ive just upped his water intake. The only major change in his diet, was moving from a 2% milk to whole milk. Ive personally never had whitw poop ao i am pretty worried right now.I was asking him if he has white poops a lot but he said theyre usually brown or "one time it was black" but to be honest, im really not sure if he pays close enough attention to his poops to remember the color of them.Im considering getting him into the doctor but i wanted to wait until he pooped again so i could see if it is still white. I need to know if he will be fine in school tomorrow until when he is done to see the doctor, or if i should bring him now/first thing in he morning.Thanks via /r/Parenting http://ift.tt/2rkEL2b