Food Poisoning

Diagnosis

To diagnose the cause of your symptoms, your doctor will send a stool sample to be examined in a laboratory. Your doctor also may want to take a sample of your blood for testing. If you have some of the food that might have made you sick, ask your doctor if a sample should be tested for infectious organisms or a toxin. The sample can be cultured in a laboratory, which means it is placed on a special material that encourages organisms that may be in the sample to grow, so they can be identified.

Up to 80% of food poisoning is related to eating commercially prepared foods or institutional foods. In such cases, questioning others who have eaten the same foods may help to determine the cause.

Information about the length of time between eating the food and the beginning of symptoms can help in diagnosing the problem:

• Less than six hours suggests that the infection was caused by a type of bacteria capable of creating a toxin in the food before it was eaten (such as staphylococcal food poisoning)

• Twelve hours or more suggests the infection was caused by a type of bacteria that makes a toxin after the food is eaten (such as certain types of E. coli), or else a bacteria, virus or parasite that can damage the cells lining the intestine (such as salmonella)

Expected Duration

In general, food poisoning goes away in one to three days, although some types of food poisoning may last much longer.