Carrie A., his gastroenterologist ordered the test along with about 30 others, just to see what his tract is doing. We literally had a bucket full of poo sample jars and smear cards. That was an interesting week.
I know that fruit causes acid poo in my kidmonster. He had some really ripe pear a couple of days in a row and that led to the nastiest open sore rash I ever saw. I hate limiting his fruit, but I think I have to until his tract matures some more.
Lunarlady, thanks for the explanation! The weird thing is it doesn't seem to bother him at all -- unless he has too much fruit, which leads to nasty acid burn diaper rashes. Usually his butt looks fine -- and he has very sensitive skin. And he never seems to be in any pain pooping. So I don't know. Maybe it's nothing more than his poo reacting to the detergent in his CDs, so he's getting false positives? And re: constipating foods, he only poops once-twice a day as it is, it's not like he's having diarrhea.
We already know his tract is immature -- his iron binding capacity, for instance, is low but slowly increasing. His GI says that at age 3 he might have caught up altogether. It's just maddening not knowing if we're dealing with unknown food intolerances because apart from the acid poo, he has virtually no symptoms. And we wouldn't've known about the acid poo (apart from the fruit overdose poos) if it weren't for this test. Wonder how many people have weird poo pH without knowing about it -- just because they weren't tested!