Calling All Dog Lovers

My dog is sick, but here are his only two symptoms:
1. really bad runs 3 times today-the type of runs that when he thinks he is done he starts walking away and it is still dripping (however no accidents in the house, he is able to wait until I let him out to do)
2. loss of appetite-my dog has a very healthy appetite. I can't get the food in the bowl fast enough and he always finishes it

However,
*His attitude and behavior is normal
*Someone told me to make him rice and he ate that right up, licked the bowl clean, but he won't eat his dog food
*heart rate is normal
*belly is not hard
*white of his eyes look fine
*still drinks water
*has peed plenty today
*doesn't whine or anything

He is up to date on all his shots and he takes heartguard once a month.


Any feedback-did he just eat something that didn't agree with him?