Viral gastroenteritis (stomach flu) – Symptoms & causes

Overview

Viral gastroenteritis is an intestinal infection that includes signs and symptoms such as watery diarrhea, stomach cramps, nausea or vomiting, and sometimes fever.

The most common way to develop viral gastroenteritis — often called stomach flu — is through contact with an infected person or by consuming contaminated food or water. If you’re otherwise healthy, you’ll likely recover without complications. But for infants, older adults and people with compromised immune systems, viral gastroenteritis can be deadly.

There’s no effective treatment for viral gastroenteritis, so prevention is key. Avoid food and water that may be contaminated and wash your hands thoroughly and often.

Products & Services

Symptoms

Although it’s commonly called stomach flu, gastroenteritis isn’t the same as influenza. The flu (influenza) affects only your respiratory system — your nose, throat and lungs. Gastroenteritis, on the other hand, attacks your intestines, causing signs and symptoms such as:

• Watery, usually nonbloody diarrhea — bloody diarrhea usually means you have a different, more severe infection
• Nausea, vomiting or both
• Stomach cramps and pain
• Occasional muscle aches or headache
• Low-grade fever

Depending on the cause, viral gastroenteritis symptoms may appear within 1-3 days after you’re infected and can range from mild to severe. Symptoms usually last just a day or two, but occasionally they may last up to 14 days.

Because the symptoms are similar, it’s easy to confuse viral diarrhea with diarrhea caused by bacteria, such as Clostridioides difficile, salmonella and Escherichia coli, or parasites, such as giardia.

Viral gastroenteritis

The stomach, small intestine and large intestine (colon) are part of your digestive tract, which processes the foods you eat. Viral gastroenteritis is an inflammation of these organs caused by a virus.

When to see a doctor

If you’re an adult, call your health care provider if:

• You’re not able to keep liquids down for 24 hours
• You’ve been vomiting or having diarrhea for more than two days
• You’re vomiting blood
• You’re dehydrated — signs of dehydration include excessive thirst, dry mouth, deep yellow urine or little or no urine, and severe weakness, dizziness or lightheadedness
• You notice blood in your bowel movements
• You have severe stomach pain
• You have a fever above 104 F (40 C)

For infants and children

See your child’s health care provider right away if your child:

• Has a fever of 102 F (38.9 C) or higher
• Seems tired or very irritable
• Is in a lot of discomfort or pain
• Has bloody diarrhea
• Seems dehydrated — watch for signs of dehydration in sick infants and children by comparing how much they drink and urinate with how much is normal for them, and watching for signs such as a dry mouth, thirst and crying without tears

If you have an infant, remember that while spitting up may be an everyday occurrence for your baby, vomiting is not. Babies vomit for a variety of reasons, many of which may require medical attention.

Call your baby’s doctor right away if your baby:

• Has vomiting that is frequent
• Hasn’t had a wet diaper in six hours
• Has bloody stools or severe diarrhea
• Has a sunken soft spot (fontanel) on the top of his or her head
• Has a dry mouth or cries without tears
• Is unusually sleepy, drowsy or unresponsive

Causes

You’re most likely to get viral gastroenteritis when you eat or drink contaminated food or water. You may also be likely to get gastroenteritis if you share utensils, towels or food with someone who has one of the viruses that cause the condition.

Many viruses can cause gastroenteritis, including:

• Noroviruses. Both children and adults are affected by noroviruses, the most common cause of foodborne illness worldwide. Norovirus infection can sweep through families and communities. It’s especially likely to spread among people in confined spaces.

  In most cases, you pick up the virus from contaminated food or water. But it can also spread between people who are in close contact or who share food. You can also get the virus by touching a surface that’s been contaminated with norovirus and then touching your mouth.

• Rotavirus. Worldwide, this is the most common cause of viral gastroenteritis in children, who are usually infected when they put their fingers or other objects contaminated with the virus into their mouths. It can also spread through contaminated food. The infection is most severe in infants and young children.

  Adults infected with rotavirus may not have symptoms, but can still spread the illness. This is of particular concern in institutional settings such as nursing homes because adults with the virus unknowingly can pass the virus to others. A vaccine against viral gastroenteritis is available in some countries, including the United States, and appears to be effective in preventing the infection.

Some shellfish, especially raw or undercooked oysters, also can make you sick. Contaminated drinking water is a cause of viral diarrhea. But in many cases the virus is passed when someone with a virus handles food you eat without washing his or her hands after using the toilet.

Risk factors

Gastroenteritis occurs all over the world and can affect people of all ages.

People who may be more susceptible to gastroenteritis include:

• Young children. Children in child care centers or elementary schools may be especially vulnerable because it takes time for a child’s immune system to mature.
• Older adults. Adult immune systems tend to become less efficient later in life. Older adults in nursing homes are vulnerable because their immune systems weaken. They also live in close contact with others who may pass along germs.
• Schoolchildren or dormitory residents. Anywhere that groups of people come together in close quarters can be an environment for an intestinal infection to get passed.
• Anyone with a weakened immune system. If your resistance to infection is low — for instance, if your immune system is compromised by HIV/AIDS, chemotherapy or another medical condition — you may be especially at risk.

Each gastrointestinal virus has a season when it’s most active. If you live in the Northern Hemisphere, for instance, you’re more likely to have rotavirus or norovirus infections in the winter and spring.

Complications

The main complication of viral gastroenteritis is dehydration — a severe loss of water and essential salts and minerals. If you’re healthy and drink enough to replace fluids you lose from vomiting and diarrhea, dehydration shouldn’t be a problem.

Infants, older adults and people with weakened immune systems may become severely dehydrated when they lose more fluids than they can replace. Hospitalization might be needed so that lost fluids can be replaced through an IV in their arms. Dehydration can rarely lead to death.

Prevention

The best way to prevent the spread of intestinal infections is to follow these precautions:

• Get your child vaccinated. A vaccine against gastroenteritis caused by the rotavirus is available in some countries, including the United States. Given to children in the first year of life, the vaccine appears to be effective in preventing severe symptoms of this illness.

• Wash your hands thoroughly. And make sure your children do, too. If your children are older, teach them to wash their hands, especially after using the toilet.

  Wash your hands after changing diapers and before preparing or eating food, too. It’s best to use warm water and soap and to rub hands well for at least 20 seconds. Wash around cuticles, beneath fingernails and in the creases of the hands. Then rinse thoroughly. Carry sanitizing wipes and hand sanitizer for times when soap and water aren’t available.

• Use separate personal items around your home. Avoid sharing eating utensils, drinking glasses and plates. Use separate towels in the bathroom.
• Prepare food safely. Wash all your fruits and vegetables before eating them. Clean kitchen surfaces before preparing food on them. Avoid preparing food if you’re sick.
• Keep your distance. Avoid close contact with anyone who has the virus, if possible.
• Disinfect hard surfaces. If someone in your home has viral gastroenteritis, disinfect hard surfaces, such as counters, faucets and doorknobs, with a mixture of 5-25 tablespoons (73 to 369 milliliters) of household bleach to 1 gallon (3.8 liters) of water.
• Avoid touching laundry that may have been exposed to a virus. If someone in your home has viral gastroenteritis, wear gloves while touching laundry. Wash clothing and bedding in hot water and dry them on the hottest setting. Wash your hands well after touching laundry.
• Check out your child care center. Make sure the center has separate rooms for changing diapers and preparing or serving food. The room with the diaper-changing table should have a sink as well as a sanitary way to dispose of diapers.

Take precautions when traveling

When you’re traveling in other countries, you can become sick from contaminated food or water. You may be able to reduce your risk by following these tips:

• Drink only well-sealed bottled or carbonated water.
• Avoid ice cubes because they may be made from contaminated water.
• Use bottled water to brush your teeth.
• Avoid raw food — including peeled fruits, raw vegetables and salads — that has been touched by human hands.
• Avoid undercooked meat and fish.

More Information

Viral gastroenteritis (stomach flu) – Diagnosis & treatment

Diagnosis

Your doctor will likely diagnose viral gastroenteritis (stomach flu) based on symptoms, a physical exam and sometimes on the presence of similar cases in your community. A rapid stool test can detect rotavirus or norovirus, but there are no quick tests for other viruses that cause gastroenteritis. In some cases, your doctor may have you submit a stool sample to rule out a possible bacterial or parasitic infection.

Treatment

There’s often no specific medical treatment for viral gastroenteritis. Antibiotics aren’t effective against viruses. Treatment first involves self-care measures, such as staying hydrated.

Clinical trials

Explore Mayo Clinic studies testing new treatments, interventions and tests as a means to prevent, detect, treat or manage this condition.

Self care

To help keep yourself more comfortable and prevent dehydration while you recover, try the following:

• Let your stomach settle. Stop eating solid foods for a few hours.
• Try sucking on ice chips or taking small sips of water often. You might also try drinking clear soda, clear broths or noncaffeinated sports drinks. In some cases you can try oral rehydration solutions. Drink plenty of liquid every day, taking small, frequent sips.
• Ease back into eating. As you’re able, you can return to eating your normal diet. You might find that you can eat bland, easy-to-digest foods at first, such as soda crackers, soup, oats, noodles, bananas and rice. Stop eating if your nausea returns.
• Avoid certain foods and substances until you feel better. These include caffeine, alcohol, nicotine, and fatty or highly seasoned foods.
• Get plenty of rest. The illness and dehydration may have made you weak and tired.
• Try anti-diarrhea medications. Some adults may find it helpful to take loperamide (Imodium A-D) or bismuth subsalicylate (Pepto-Bismol, others) to manage their symptoms. However, avoid these if you have bloody diarrhea or fever, which could be signs of another condition.

For infants and children

When your child has an intestinal infection, the most important goal is to replace lost fluids and salts. These suggestions may help:

• Help your child rehydrate. Give your child an oral rehydration solution, available at pharmacies without a prescription. Talk to your doctor if you have questions about how to use it.

  Don’t give your child plain water — in children with gastroenteritis, water isn’t absorbed well and won’t adequately replace lost electrolytes. Avoid giving your child apple juice for rehydration — it can make diarrhea worse.

• Get your child back to a normal diet once hydrated. Once your child is rehydrated, introduce him or her to his or her normal diet. This might include toast, yogurt, fruits and vegetables.
• Avoid certain foods. Don’t give your child sugary foods, such as ice cream, sodas and candy. These can make diarrhea worse.
• Make sure your child gets plenty of rest. The illness and dehydration may have made your child weak and tired.
• Avoid giving your child store-bought anti-diarrheal medications, unless advised by your doctor. They can make it harder for your child’s body to get rid of the virus.

If you have a sick infant, let your baby’s stomach rest for 15-20 minutes after vomiting or a bout of diarrhea, then offer small amounts of liquid. If you’re breast-feeding, let your baby nurse. If your baby is bottle-fed, offer a small amount of an oral rehydration solution or regular formula. Don’t dilute your baby’s already-prepared formula.

Preparing for your appointment

If you or your child needs to see a doctor, you’ll likely see your doctor first. If there are questions about the diagnosis, your doctor may refer you to an infectious disease specialist.

What you can do

Preparing a list of questions will help you make the most of your time with your doctor. Some questions you might want to ask your or your child’s doctor include:

• What’s the likely cause of the symptoms? Are there other possible causes?
• Is there a need for tests?
• What’s the best treatment approach? Are there any alternatives?
• Is there a need to take medicine?
• What can I do at home to ease the symptoms?

What to expect from your doctor

Some questions the doctor may ask include:

• When did symptoms begin?
• Have the symptoms been continuous, or do they come and go?
• How severe are the symptoms?
• What, if anything, seems to improve symptoms?
• What, if anything, appears to worsen symptoms?
• Have you been in contact with anyone with similar symptoms?

What you can do in the meantime

Drink plenty of fluids. As you’re able, you can return to eating your normal diet. You might find you can eat bland, easy-to-digest foods at first. If your child is sick, follow the same approach — offer plenty of fluids. When possible, start having your child eat his or her normal diet. If you’re breastfeeding or using formula, continue to feed your child as usual. Ask your child’s doctor if giving your child an oral rehydration solution, available without a prescription at pharmacies, would help.

Water diarrhea – causes and treatment of watery diarrhea

Co-author, editor and medical expert – Klimovich Elina Valerievna.

Editor and medical expert – Harutyunyan Mariam Harutyunovna.

Number of views: 1,308,183

Date last updated: 2 Contents:

How water is absorbed in the intestines
Causes of secretory diarrhea
What to do if the diarrhea is watery?

Diarrhea can have different causes, but is always accompanied by changes in intestinal absorption of water and electrolytes. And with secretory diarrhea, this process is not only disrupted, but is replaced by active transport of electrolytes into the intestinal lumen and, after them, water. The osmolar pressure of the intestinal contents becomes lower than the osmolar pressure of the blood plasma. This supports the diffusion of water into the intestinal lumen and is fraught with rapid dehydration due to the development of diarrhea with water. At the same time, the stool is liquid, plentiful (more than 1 liter), defecation is painless, and fasting practically does not change the nature and quantity of bowel movements. If secretory diarrhea is accompanied by malabsorption of bile acids or a decrease in the contractile function of the gallbladder, the watery stool becomes bright yellow or greenish in color. This is called hologenic diarrhea.

How water is absorbed in the intestines

Every day a person consumes about 2 liters of water. It is found not only in drinks, but also in all the foods eaten. In addition, fluid enters the lumen of the digestive tract as part of the digestive secrets. And about 7 liters are released per day! This includes 1.5 liters of saliva and pancreatic juice, 2.5 liters of gastric juice, half a liter of bile and a liter of intestinal secretions. Total enters the intestinal lumen daily up to 9liters of water, and only 100-200 ml (that is, about 2%) of this volume is excreted with feces. The walls of the small intestine absorb up to 80% of all liquid, and 90% of the remaining amount is absorbed in the large intestine.

In this case, water is absorbed secondarily and passively, following the active transport of electrolytes through the walls of the digestive tract. Sodium ions play the most important role in this process, but potassium and chlorine also take an active part. All these electrolytes enter the intestine with food and digestive juices and are actively absorbed. At the same time, the final absorption of water and absorption up to 90% sodium occurs in the large intestine. As a result, rather dense fecal masses are normally formed here.

Causes of secretory diarrhea

Exogenous

• Drugs. Some medications cause watery diarrhea. They increase the osmotic pressure inside the intestine or change the transport of ions in the intestinal wall. Watery diarrhea often occurs when taking laxatives, diuretics, drugs for the treatment of bronchial asthma and thyroid diseases. Cholinergic drugs have a great influence. These include certain myasthenic, cardiotonic, and antihypertensive agents, as well as antidepressants and agents for the treatment of dementia.
• Toxins. Secretory diarrhea can occur against the background of poisoning with fungi, arsenic, organophosphorus compounds, insecticides, alcohol and a number of other drugs.
• Viral and bacterial infections . A number of infections cause watery diarrhea due to exposure to the pathogens themselves and their toxins. These are cholera, yersiniosis, some strains of Escherichia coli and staphylococci that produce enterotoxins.

Endogenous

• Hereditary diseases. There is a congenital secretory pathology (chloridorrhoea, sodium diarrhea), the cause of which lies in the mutation of the genes of intestinal wall transport proteins. The disease manifests itself in a child from birth.
• Hormone-producing tumors. Pathological secretion of ions and water in the intestine can be promoted by some tumors – medullary thyroid carcinoma, VIPoma, gastrinoma, mastocytoma and others.
• Bile salts. Ingestion of non-adsorbed bile acids and free long-chain fatty acids into the large intestine leads to the secretion of water into the intestinal lumen. The reason for this is a violation of the absorption of bile acids in diseases (for example, in Crohn’s disease) or due to a decrease in the absorption area. This happens after resection of more than 100 cm of the ileum.

What if the diarrhea is watery?

Loperamide (active ingredient IMODIUM ^® Express) binds to opiate receptors in the intestinal wall, inhibits the local production of acetylcholine, calmodulin and prostaglandins. Calcium channels are also blocked, the permeability of plasma membranes decreases and the activity of intestinal motility decreases. As a result, the secretion of water into the intestinal lumen is significantly reduced, and its absorption is enhanced. Therefore, IMODIUM ^® Express can be used in the complex treatment of secretory diarrhea (water diarrhea).

The information in this article is for reference only and does not replace professional medical advice. For diagnosis and treatment, contact a qualified specialist.

“Imodium is contraindicated for use in children under 6 years of age.”

See also:

• Bear disease

Treatment of the gastrointestinal tract – Services

Digestive diseases are by far the most common of all diseases of the internal organs. The “field of responsibility” of gastroenterology is the treatment of diseases of the esophagus, stomach, pancreas, intestines, gallbladder and liver.

Digestion is the process of mechanical and chemical processing of food, as a result of which nutrients are absorbed and assimilated by the body, and decay products and undigested products are removed from it.

Digestion is the initial stage of metabolism. With food, a person receives energy and all the necessary substances for the renewal and growth of tissues. However, the proteins, fats and carbohydrates contained in food, as well as vitamins and mineral salts, are foreign substances for the body and cannot be absorbed by its cells. First, these substances must be converted into smaller molecules that are soluble in water and lack specificity. This process takes place in the digestive tract and is called digestion. The causes of indigestion are insufficient secretion of gastric juice or a violation of the evacuation of contents due to a pathological process in any organ of the digestive system.

Manifestations of indigestion: loss of appetite, feeling of heaviness, fullness in the epigastric region, nausea, sometimes vomiting, diarrhea or constipation, bloating.

Symptoms of gastrointestinal diseases:

• colicky or aching girdle pain, headaches, irritability;
• dyspeptic disorders:
  • nausea
  • vomiting
  • belching
  • heartburn
  • appetite disorder
  • bad taste in the mouth
  • stool retention
  • frequent loose stools
  • flatulence
• jaundice.

Causes of diseases of the gastrointestinal tract

The modern rhythm of life, constant stress, unhealthy diet, unfavorable environmental conditions – all this has an extremely negative effect on the state of the human body, including the functioning of the gastrointestinal tract.

The number of patients with chronic gastroenterological diseases is growing every year. And often the cause of the flow of the disease into a chronic form is self-medication.

Please note

Do not self-medicate! This will only aggravate the course of the disease, bringing only a temporary improvement in the condition.

Dyspepsia

Dyspepsia is a collective term for digestive disorders of a functional nature arising from insufficient secretion of digestive enzymes or poor nutrition.

Dyspepsia is distinguished:

• fermentative
• putrid
• fatty.

Fermentative dyspepsia is associated with excessive consumption of carbohydrates (sugar, honey, flour products, fruits, grapes, peas, beans, cabbage, etc.), as well as fermentation drinks (kvass). As a result, conditions are created in the intestine for the development of fermentative flora.

The cause of putrefactive dyspepsia is the consumption of predominantly protein foods, especially lamb, pork meat, which is digested more slowly in the intestines. Sometimes putrefactive dyspepsia occurs due to the use of stale meat products in food.

Fatty dyspepsia occurs as a result of excessive consumption of slowly digested, especially refractory, fats (pork, lamb). Dyspepsia may accompany gastritis, pancreatitis.

Symptoms of dyspepsia

• Fermentative dyspepsia – bloating, rumbling in the intestines, release of a large amount of gases; frequent, faintly colored loose, frothy, sour-smelling stools.
• Putrid dyspepsia – diarrhea with a rich dark color of feces and a putrid odor. Against the background of general intoxication with decay products, patients often complain of a deterioration in appetite, weakness, and a decrease in efficiency.
• With fatty dyspepsia, stools are light, plentiful, with a greasy sheen.

Treatment of dyspepsia

Drug therapy includes enzyme preparations.

As a symptomatic treatment of dyspepsia, the following drugs can be used: Almagel, Maalox and other acid-reducing agents; drugs that reduce gastric secretion – omeprazole, ranitidine, famotidine, etc.; enzyme preparations – acidinpepsin, abomin, pancreatin, etc. ; prokinetics – motilium, etc.; preparations for the restoration of microflora – bifikol, colibacterin and a number of other groups.

Normalization of nutrition plays a very important role in the treatment of dyspepsia.

Fasting is usually prescribed for 1–1.5 days, then:

Pay attention

It is necessary to identify and treat the underlying disease that caused dyspepsia! All kinds of folk remedies can relieve the symptoms, but the reason why they arose will not be removed! The disease will manifest itself again and again, and the disease that caused it will go into a chronic stage, in which the treatment will be much more difficult or not beneficial at all.

If any dyspeptic symptoms appear and if they last for a long time, for diagnosis, correct diagnosis and further treatment, you should contact a gastroenterologist at the Medline Medical Center in Barnaul.