Still Sick, What to Do

So last Thursday after dinner Tanner said "my tummy hurts". Sure it does, now go get in the shower. That night he wakes us up saying he is sick and he wants a bucket by his bed. Okay, maybe he is sick. Friday he stayed home from school and laid around all day and didn't eat much. Saturday he woke up, ate breakfast, cleaned, played, etc. By Saturday evening he was laying all over the floor, low energy. Sunday we just laid around and watched tv all day, didn't eat much. Monday he stayed home from school again but was acting pretty normal in the morning and early afternoon, then he crashed again. While I was at the hospital that day, my hubby took him to the doctor. They said it was just viral (sometimes kids get the stomach flu and never throw up). Yeah, that night he finally threw up and literally 5 minutes later he was playing and feeling great. Tuesday he went to school, everything normal that day. Wednesday he slept in till we had to wake him to get ready for school. He said he was sick after eating a little breakfast, but 30 minutes later he was playing so I made him go to school (I know I'm mean), but he was just fine all day. This morning we had to wake him again, he didn't eat much, but was acting fine, so we sent him to school. The school had to call me to come pick him up because he couldn't keep his head off his desk. When I got him he was miserable and has been laying down since. This is so not like any other sickness we have ever had, it makes me worried that it is something more then just a stomach virus. And if it is viral are we all going to get this. Not what I want to be dealing with. I really do wish a 6 year old could describe exactly what he was feeling, so I could know more. Anyhow....