i don't have any advice so to speak - i know it seems since my DX that every color imaginable has shown up at one time or another in the supreme white bowl -
so the question to ask is what has changed in the last week or 2 ? food wise, drink wise, med, vitamin or supplement wise ?
any extra stress or change in sleep habits ? any other change poop wise - more ? less ?
does he have any existing health issues that may be contributing ?
being a typical guy, i most usually tend to ignore things like this for a year or 2 before small concern is warranted - then i ignore that for a while
just keep an i on it - probably just a little blip but still cause for taking notice -
hopefully things get back to normal soon -