How long does canned food last?

So here's the deal, we began to tear down an old house that had been abandoned since around the 1980s. In the kitchen pantry we found a lot of canned food. I was hungry, and I hadn't ate since lunch time yesterday. So I found a can of Van Camps Pork and Beans and opened it up. It looked okay and didn't smell to bad, so I ate it. The can looked pretty old, some rust on it and it didn't even have a nutrition label on it. A few hours later I didn't feel so good and I have diarrhea now. Should I be concerned?