JACKSONVILLE, Fla. -

The hundreds of bags of lettuce recalled from Dole reminded us all how vulnerable we are to food-borne illnesses. Salmonella was the concern and it infects close to 150,000 people every year.   Dr. Spencer Topp with University of Florida Emergency Medicine at Shands says he's seen it all when it comes to stomach bugs and the challenge is diagnosing it. 

"A lot of times in the beginning they present the same especially here in the ER we never really know what we're dealing with," say Topp.

Unless there's a pattern, like people coming in that have all eaten the same food or at the same restaurant, doctors treat the symptoms. The No. 1 concern is dehydration.

"We want to make sure we're drinking a lot of water, or Gatorade, if it's a child Pedialyte and looking for the symptoms of dehydration," says Topp.

The signs of dehydration are a dry, sticky mouth, not urinating, few tears when crying, headache, constipation, or dizziness.  Those are symptoms you need to drink but here are some symptoms that indicate you need to see your doctor.

"Fevers are always concerning, blood in your stool is not normal, and then symptoms that persist more than a day or two," says Topp.

Dr. Topp points out whether it's food poisoning or a viral gastroenteritis it should clear up within 24 to 48 hours.