Causes

E. coli is a type of bacteria that normally lives in the intestines of humans and animals without causing any problems. However, certain types (or strains) of E. coli can cause food poisoning. One strain (E. coli O157:H7) can cause a severe case of food poisoning.

Bacteria may get into your food in different ways:

• Meat or poultry may come into contact with intestinal bacteria when being processed
• Water that is used during growing or shipping may contain animal or human waste
• Improper food handling or preparation

Food poisoning often occurs from eating or drinking:

• Any food prepared by someone who did not wash their hands properly
• Any food prepared using unclean cooking utensils, cutting boards, or other tools
• Dairy products or food containing mayonnaise (such as coleslaw or potato salad) that have been out of the refrigerator too long
• Frozen or refrigerated foods that are not stored at the proper temperature or are not reheated properly
• Raw fish or oysters
• Raw fruits or vegetables that have not been washed well
• Raw vegetable or fruit juices and dairy products
• Undercooked meats or eggs
• Water from a well or stream, or city or town water that has not been treated

Although not common, E. coli can be spread from one person to another. This may happen when someone does not wash their hands after a bowel movement and then touches other objects or someone else's hands.

Symptoms

Symptoms occur when E. coli bacteria enter the intestine. The time between being infected and developing symptoms is usually 24 - 72 hours.

Diarrhea that is sudden, severe, and often bloody is the most common symptom.

Other symptoms may include:

• Fever
• Gas
• Loss of appetite
• Stomach cramping
• Vomiting (rare)

Symptoms of a rare but severe E. coli infection include:

• Bruises that happen easily
• Pale skin
• Red or bloody urine
• Reduced amount of urine

Exams and Tests

Your health care provider will examine you for signs of food poisoning, such as pain in the stomach and signs your body does not have as much water and fluids as it should, called dehydration.

Laboratory tests of your food of your stools may be done to determine if E.coli is causing your symptoms.

Treatment

You will usually recover from the most common types of bacterial gastroenteritis within a couple of days. The goal of treatment is to make you feel better and avoid dehydration.

These things may help you feel better if you have diarrhea:

• Drink 8 to 10 glasses of clear fluids every day. Water is best.
• Drink at least 1 cup of liquid every time you have a loose bowel movement.
• Eat small meals throughout the day, instead of 3 big meals.
• Eat some salty foods, such as pretzels, soup, and sports drinks.
• Eat some high potassium foods, such as bananas, potatoes without the skin, and watered-down fruit juices.

Give your child fluids for the first 4 to 6 hours. At first, try 1 ounce (2 tablespoons) of fluid every 30 to 60 minutes.

Try an over-the-counter drink, such as Pedialyte or Infalyte. Do not water down these drinks. Pedialyte is also available as a popsicle.

Watered-down fruit juice, or broth, may also help.

See also: Diarrhea in children

If you have diarrhea and are unable to drink fluids because of nausea or vomiting, you may need to go to the hospital to receive fluids through a vein (IV). This is especially true for young children.

If you take diuretics, talk to your health care provider. You may need to stop taking the diuretic while you are sick. Never stop or change medications without talking to your health care provider and getting specific instructions.

Antibiotics are usually not prescribed for most common types of bacterial gastroenteritis, unless the diarrhea is extremely severe.

Do not use over-the-counter medicines to treat diarrhea without talking to your doctor first. They should not be given to children.

Outlook (Prognosis)

You usually get better in a few days, with proper fluids. Some patients may need to stay in the hospital if they become very dehydrated.

Possible Complications

Certain types of E. coli can cause severe anemia or even kidney failure.

When to Contact a Medical Professional

Call for an appointment with your health care provider if you have:

• Blood or pus in your stools
• Black stools
• Stomach pain that does not go away after a bowel movement
• Symptoms of dehydration (thirst, dizziness, light-headedness)
• Diarrhea with a fever above 101°F (100.4°F in children)
• Recently traveled to a foreign country and developed diarrhea

Also call your doctor if:

• The diarrhea gets worse or does not get better in 2 days for an infant or child, or 5 days for adults
• A child over 3 months old has been vomiting for more than 12 hours; in younger babies, call as soon as vomiting or diarrhea begins

Prevention

Careful hand washing may be helpful. Do not drink untreated or possibly contaminated food or water. Always cook meats well, especially ground meats. Cook meats at high enough temperatures to kill bacteria.

See also: Preventing food poisoning

Alternative Names

Traveler's diarrhea - E. coli; Food poisoning - E. coli; E. coli diarrhea; Hamburger disease

References

Schiller LR, Sellin JH. Diarrhea. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger & Fordtran’s Gastrointestinal and Liver Disease. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2010:chap 15.

Update Date: 1/5/2012

Reviewed by: Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; George F. Longstreth, MD, Department of Gastroenterology, Kaiser Permanente Medical Care Program, San Diego, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.