I can't really say what happened to you...you should have saved a sample of the food (if there was any left, if you didn't eat it all) and sent it to the health department if you were worried about poisoning. A stool sample sent to a lab from that night would have been usefull as well. The bad thing about samples, is that my Gastro. Doc said that they have to be very fresh for a lab, rushed there within 2 hours. If anything happens at night, even using the refridgerator isn't good enough for accurate results.
I used to have symptoms a little similar to yours, and when they first started happening, i suspected food poisoning. I would have severe diarrhea after initial abdominal cramps, be in the bathroom for an hour at a time, only to rush back after a few minutes after leaving it. Sometimes the pain would be so bad i'd be on the verge of lifting up the phone to call 911 or have someone drive me to the hospital. It felt like my intestines would swell and explode, like some big fist was squeezing them.
Then it would be all over, once all food left my body, and i'd be tired and shaken, sore, but alright.
This would happen once, maybe twice a month, then another month would go by where I would be fine, then it would hit again. They were more like attacks than somachaches. They became worse overtime.
Once at work, I was doubled over with pain then ran to the bathroom. I had dysentary (blood in the stool) and not a small bit of it either. Unlike your chills, I felt like I was on fire, but at the same time my skin was cold to the touch. I wanted to take off all my clothes, I was that hot inside. But I had no fever. The usual cramps came and I wanted to die. I was on the verge of passing out from the pain ( I had actually done that and woke up on the bathroom floor a few times before.) My pulse hammered and I felt like at any moment I could sweat, but did not.
But once again, once all the food left my body, I was fine, just exhaused.
That was 2001, and my biggest attack. They kept happening, usually once a month. I kept thinking it was poison, but nobody gets poisoning that often. It was eventually found, in 2004, that I had a gallstone, as large as a walnut. So many different foods can upset gallstones that it seems like an attack can come at any time. Onions, however, are particularly irritating. The stones actually move around and can get lodged in ducts, then the body tries to squeeze them out of the ducts by contracting muscles. I don't know why certain foods cause this, but pork, onions, spicy foods, duck and goose, sausage, cabbage, and anything really greasy will upset the stone. Carbonated beverages also. And alcohol.
Try going to the grocery store and buying as many of these things as you can, eat them, and see what happens. Have a Vicodin or morphine pill handy tho in case you have an attack. (But DONT take pills with alcohol!)
Its the only way I found to stop the pain and contractions. You can also have a simple sonigram done, that's how mine was found. Anyway that food list is just the tip of the iceberg...there are so many forbidden foods with stones that it seems you can't eat anything without facing the possibility of an attack.
But if it happens again, take samples to be tested. It's the only way to truly know if it's poison. Staph, if eaten can cause really bad things too, and it might benefit your community if that Arbys, should they be found to do anything wrong, is shutdown or run by somebody else.