Yeah, once he goes to the bathroom, he'll feel better.
Also, there is an enterovirus going around. We had it. I took my daughter in, because it looked like the flu (headache, stuffy head, general achiness, fever) - there is a flu strain going around her school that wasn't in the vaccine. Doc told me that it's just an enterovirus. And a fairly mild one, at that. She said the major symptom differences are a lower fever - above 104, think flu. And bad gas, with bloating. Some kids also get naseau and diarrhea, but they all get bad gas. Think 3-5 days of it. And, by the way, it's highly contagious. Our whole house had it.