Diarrhea, vomiting, and many other unpleasant symptoms can be caused by gastrointestinal infections.
Gastrointestinal infections may be caused by bacteria, viruses, and parasites.
Care usually focuses on staying hydrated and restful, but may vary depending on the type of infection.
This paper breaks down the causes, mechanisms, and treatments for a number of severe gastrointestinal infections.
Types
There are three main types of gastrointestinal infections:
- bacterial
- viral
- parasitic
Bacterial
Bacterial gastrointestinal infections include foodborne infections and food poisoning.
Common sources of bacterial gastrointestinal infections include:
- Salmonella
- Escherichia coli, or E. coli
- Clostridium perfringens
- Listeria
- Staphylococcus, or a staph infection
Although almost any contaminated food can cause infection, there are some foods that present more danger than others. This includes:
- undercooked or raw meat, eggs, or poultry
- unpasteurized dairy and juices
- contaminated water
- food, particularly meat and egg products, that is not refrigerated well
- deli meats
- unwashed or raw fruits and vegetables
Furthermore, people who have gastrointestinal bacterial infections will spread the bacteria to the food they touch. When they eat the food, this food could then infect another.
Viral
Viral gastrointestinal infections are very common and these are sometimes referred to as the gastrointestinal flu.
Norovirus is a type of Gastroenteritis Virus. Norovirus causes 19 to 21 million cases of stomach flu in the United States each year, according to the National Institute for Diabetes and Digestive Diseases (NIDDK).
Most viruses that can cause viral gastrointestinal infections are less common in the U.S. Vaccines can avoid other forms of viral infections, including rotavirus.
Parasitic
Intestinal helminths, or worms, and protozoan parasites cause infections with the gastrointestinal parasites.
Giardiasis and cryptosporidiosis are the two most common infections with the parasites.
These parasites can spread in the soil by contact with human feces. Such infections may also be contracted by people drinking or bathing with polluted water.
Some infections of the parasites can spread from animals to people. Which include toxoplasmosis, in which individuals may come into contact in cat feces.
Symptoms
Most gastrointestinal infections have similar symptoms, though they may vary in severity.
Symptoms of gastrointestinal infections include:
- diarrhea
- nausea
- vomiting
- stomach cramps
- loss of appetite
- a fever
- muscle aches
- an electrolyte imbalance
- gas and bloating
- unintentional weight loss
Most gastrointestinal viral illnesses start unexpectedly and last less than a week, although they may last longer.
Bacterial infections may be similar to viral infections, but some may have a greater chance of causing high fever or bloody diarrhea.
Parasitic gastrointestinal infections often cause diarrhea to cause blood or mucus, and can last before care is given to a person.
When to see a doctor
Most people do not need to see a doctor if they’re having gastrointestinal infection symptoms.
However, if a person experiences any of the following symptoms, the NIDDK advises seeing a doctor right away:
- severe pain in the abdomen
- a high fever
- diarrhea that lasts longer than 2 days
- black or tarry stools
- six or more loose stools per day
- frequent vomiting
- changes in mental state
Adults should also see a gastrointestinal infection doctor if they can not hold the liquid down or show signs of dehydration, including:
- extreme thirst
- dark, infrequent urine
- sunken cheeks and eyes
- a dry mouth
- skin that does not flatten back after pinching
- lightheadedness
Some people should always consult a doctor about gastrointestinal infections, as they are at higher risk of complications. Including:
- pregnant women
- people with a compromised immune system
- older adults
- infants and young children
Treatment
Many gastrointestinal infections, particularly parasite infections, require a doctor’s prescription medication. However, without medical treatment or intervention, no cases of gastrointestinal illnesses will get better.
Most of the time a person can support their immune system by having plenty of rest and drinking lots of water to fight off the infection at home.
In severe cases, rehydration can require supportive treatment at a hospital.
Home remedies
People with a gastrointestinal infection can help treat the illness at home by:
- resting
- taking sips of water frequently
- using over-the-counter medications with caution
- eating bland, easy-to-digest food when feeling better
Prevention
Many gastrointestinal diseases are highly contagious but a person may take many steps to help prevent them from spreading.
The Centers for Control and Prevention of Diseases (CDC) recommends that a person do the following to prevent viral infections:
- wash their hands well with soap and water
- not substitute alcohol-based hand sanitizer for hand washing
- practice food safety, including washing fruits and vegetables and cooking meats
- avoid cooking or preparing food for another person while ill
- disinfect hard surfaces with bleach
- carefully launder clothes or linens
To avoid a bacterial gastrointestinal infection, the CDC recommend:
- washing hands and surfaces before, during, and after food preparation
- separating raw meats, seafood, poultry, and eggs from prepared food
- cooking food to a safe internal temperature and avoiding undercooked food
- refrigerate food below 40°F (4°C) within 2 hours of cooking
People at higher risk of gastrointestinal infection and its complications should also avoid undercooked or raw animal foods, unpasteurized dairy products and juices, and raw sprouts.
To avoid a parasitic gastrointestinal infection, a person should:
- practice good hygiene including hand washing
- avoid contaminated food and water
- use caution when traveling to areas where parasitic infections are more common
- take precautions to prevent toxoplasmosis, including avoiding the cat litter box if pregnant
Summary
Gastrointestinal diseases can be parasitic, bacterial or viral. The symptoms are unpleasant regardless of the cause, and can include diarrhea, abdominal cramping and nausea.
Most infections should heal by themselves, but if a person has dehydration symptoms or other complications they should see a doctor.
Meanwhile, having plenty of rest and fluids is necessary to promote a speedy recovery.
