Well, I checked the breakfast sausage and it didn't list any ingredients with gluten in them. Plus, that wouldn't explain my symptoms last week, since I ate that for the first time yesterday.
It's just really weird because I was being very careful. I ate a gluten free burger at Red Robin on Tuesday but my stomach continued to be great until Thursday, so I don't think that could have anything to do with it.
(sorry for the delayed response, I have limited internet)