Whenever I get inflammation in my gut, I start running a temperature - not by much, just as you say, a low grade fever. It tends to come and go though, probably worst at night. During the day my temperature bounces - one minute sweats, the next chills. And feeling bleh is part of what goes with it.
I don't know if it is the disease or a response to it, but either way it is a harbinger of trouble, so maybe worth mentioning to your doc.