@fBoyle-- Yes, if it's a stomach bacterial infection. This actually happened to me a few years ago. The same symptoms could be caused by parasitic infections as well. You need to see a doctor, especially if you think you might have eaten unclean food or drank unclean water.
I had a stomach bacteria infection when I was in college. I had constant heartburn due to acid reflux, fatigue, nausea and stomach cramps. It was awful and I even suspected that I had stomach ulcers. I was given a breath test by my doctor which showed that I have a stomach bacteria called h.pylori. It's actually a common bacteria but causes severe symptoms in some people. I was treated with antibiotics and the symptoms went away.
These symptoms can also be due to parasitic infection in the intestines. If you traveled abroad recently or ate at dubious restaurants, the risks are high. So see a doctor right away.