Gastroenteritis

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Introduction

Gastroenteritis is irritation and inflammation of the stomach and intestines.  It is most frequently caused by viral or bacterial infection.  Symptoms of gastroenteritis include nausea, vomiting, diarrhea, and abdominal pain. Usually, treatment is aimed at preventing dehydration.  Certain bacterial causes are treated with antibiotics.  Gastroenteritis typically lasts from a few days to a week or more, depending on the cause.
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Anatomy

Whenever you eat and drink, food travels through your digestive system for processing.  Your body absorbs nutrients and removes waste products via your digestive system.  When you eat, your tongue moves chewed food to the back of your throat.  When you swallow, the food moves into the opening of the esophagus.  Your esophagus is a tube that moves food from your throat to your stomach.
 
Your stomach produces acids to break down food for digestion.  Your stomach processes the food you eat into a liquid form.  The processed liquid travels from your stomach to your small intestine.  The liquid solidifies as it moves through the large intestine, forming a stool.  The stool is eliminated from your body when you have a bowel movement
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Causes

There are several causes of gastroenteritis.  It is most frequently caused by viral or bacterial infection.  Viruses are found in contaminated food and water.  Poor hand washing most commonly transmits viruses.  Bacterial causes include traveler’s diarrhea, food poisoning, handling undercooked meat or poultry, and handling reptiles with the bacteria. 

Parasites, chemical toxins, and food intolerance can cause gastroenteritis.  Parasites are found in contaminated drinking water or swimming pools.  Chemical toxins are most frequently contained in seafood, certain medications, and metals including lead, mercury, and arsenic.  Food allergies or lactose intolerance, the inability to digest milk or cheese products, can also cause gastroenteritis.

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Symptoms

Common symptoms of gastroenteritis include nausea, vomiting, diarrhea, a low fever, and cramping or abdominal pain.  You should call your doctor if you feel weak, dizzy, or experience serious symptoms.  More serious symptoms include a swollen or painful abdomen, fever higher than 101°, vomiting that lasts for more than 48 hours, bloody bowel movements, and dehydration.  Extreme thirst, dry mouth, little urine production, and a lack of tears are signs of dehydration.  You should have someone take you to a hospital emergency room if you are sleepy or unaware of your surroundings.
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Diagnosis

Your doctor can start to diagnose gastroenteritis by reviewing your medical history and conducting a physical examination.  You should tell your doctor about your symptoms and any possible exposures to contaminants or toxins.  Your doctor may test your blood and stool to help determine the cause of your illness. Your doctor will also evaluate how dehydrated you are.
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Treatment

The main goal of treatment for gastroenteritis is to rehydrate.  Fluids, salts, and minerals need to be replaced.  Your doctor may recommend hydration drinks for your infant or child.  People with severe dehydration may need fluid replacement via an IV line. 
 
Certain bacteria are treated with antibiotics.  Antibiotics are not a treatment for viruses.  Medications may be recommended to reduce vomiting.  Gastroenteritis typically lasts from a few days to a week or more, depending on the cause.  Your doctor will instruct you on how to gradually increase your diet to solid foods after your illness has stopped.
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Prevention

You can prevent the transmission gastroenteritis with good hand washing.  Hands should be washed thoroughly after going to the bathroom and before handling food.  You should avoid contaminated food or water.  Enzyme supplements are available to help digest foods with lactose.  Additionally, there are many lactose-free products available on the market.
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Am I at Risk

Infants, children, the elderly, and people with suppressed immune systems have the highest risk for getting severe symptoms from gastroenteritis.  Your risk is increased if you travel or live in areas with poor sanitation.  You are at risk if you eat or drink contaminated food or water.
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Complications

You should call your doctor if you feel weak, dizzy, or experience serious symptoms.  More serious symptoms include a swollen or painful abdomen, fever higher than 101°, vomiting that lasts for more than 48 hours, bloody bowel movements, and dehydration.  Extreme thirst, dry mouth, little urine production, and a lack of tears are signs of dehydration. You should have someone take you to a hospital emergency room if you are sleepy or unaware of your surroundings.

 
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This information is intended for educational and informational purposes only. It should not be used in place of an individual consultation or examination or replace the advice of your health care professional and should not be relied upon to determine diagnosis or course of treatment.

The iHealthSpot patient education library was written collaboratively by the iHealthSpot editorial team which includes Senior Medical Authors Dr. Mary Car-Blanchard, OTD/OTR/L and Valerie K. Clark, and the following editorial advisors: Steve Meadows, MD, Ernie F. Soto, DDS, Ronald J. Glatzer, MD, Jonathan Rosenberg, MD, Christopher M. Nolte, MD, David Applebaum, MD, Jonathan M. Tarrash, MD, and Paula Soto, RN/BSN. This content complies with the HONcode standard for trustworthy health information. The library commenced development on September 1, 2005 with the latest update/addition on February 16, 2022. For information on iHealthSpot’s other services including medical website design, visit www.iHealthSpot.com.