I got the stomach flu on Dec 19, and had just 1.5 days of diarrhea, no vomiting. On the 3rd day, I had significant gas pains in my belly and chest/back pain (which I have had the pain before, and was told it could be gall bladder but tests were not conclusive at the time). The 4th day I was a bit better. On days 5 and 6, I have had the worst gas pain and foul smelling gas I have ever experienced and tonight (6th day), I passed gray clay like stool. My appetite has been very poor and I get waves of nausea and gas. Should I get checked out further or is this just a really bad stomach flu?