If everyone in America who contracts a food-borne disease each year ran to their doctors' offices, the medical system (or at least the health insurance industry) would probably collapse. Fortunately the vast majority of sufferers recover within a few days without medical intervention. Many never realize that they even had a food-borne infection.

Certainly anyone at high risk for complications - including the very young, the very old, those with weakened immune systems, pregnant women, and people with liver disease - ought to consult a physician if gastrointestinal symptoms are severe. Occasionally people who don't fall into a high-risk group can also develop serious complications from a food-borne infection and thus may also benefit from prompt medical attention.

The next time you or a loved one experiences gastroenteritis (nausea with or without vomiting, some degree of abdominal pain, plus diarrhea), ask the following questions. If you answer yes to any of them, or if you are in doubt about how to answer them, you should consult your family physician:

• Have the symptoms lasted for more than two days?
• Is there a fever?
• Is the diarrhea very watery or explosive?
• Are there signs of dehydration? If enough fluid is lost through diarrhea or vomiting, it can affect the body's salt balance. Children can become dehydrated more quickly than adults. The main symptoms of dehydration are intense thirst, dry lips and tongue, increased heart and breathing rates, weakness, and dizziness.
• Is blood mixed in with the stools? Making this determination can be tricky. If the water in the toilet bowl is bloody, but blood is not interspersed throughout the feces, the cause could be hemorrhoids or an anal fissure. Blood laced into the feces indicates that the problem is originating higher up in the intestinal tract and may possibly stem from a food-borne infection. See a doctor if you are not sure. Any time a child has bloody diarrhea seek medical attention immediately and insist on a stool test for E. Coli and other common food-borne pathogens.
• Is pus or mucus (whitish-gray in color) mixed in with the stools?
• Have bowel movements been unusual in frequency or consistency for more than two days?
• Do symptoms include shivers or chills?
• Has anyone else in your family been sick with similar symptoms?

Don't let an absence of fever lull you into a false sense of safety if you are experiencing severe GI symptoms. The rare but potentially fatal complication of E. Coli O157:H7, hemolytic uremic syndrome (HUS), doesn't usually generate a high fever, although a low-level fever is quite common.

(Reprinted with permission from the authors of Safe Eating: Protect Yourself Against E. Coli, Salmonella, and other Deadly Food-Borne Pathogens by David W. Acheson, M.D., and Robin K. Levinson, Dell Books, 1999.)