Gastroenteritis is an inflammatory disease of the gastrointestinal tract, the most prominent symptom of which is diarrhea. The name is made up of gastro- (medical for stomach), -enter (medical for intestine) and -itis (medical for inflammation). Gastroenteritis is also commonly known as stomach flu.
Gastroenteritis causes inflammation of the mucous membrane that lines the entire gastrointestinal tract. In most cases, this inflammation is caused by pathogens, but it can also be caused by poorly tolerated medication or chemical toxins, such as metals or certain plant substances. Food intolerances also ultimately lead to an abacterial (i.e. without evidence of germs) inflammation of the mucous membrane.
Even though the mucous membrane can become inflamed in the entire gastrointestinal tract (i.e. from the stomach to the rectum), the small intestine is most frequently affected. Involvement of the stomach is also not uncommon, but the large intestine is only affected in exceptional cases.
Gastroenteritis can have various causes. In most cases, especially in the winter months, gastroenteritis is triggered by viruses. Bacteria and parasites can also cause the disease. Rota and noroviruses are most frequently responsible for gastroenteritis.
An infection caused by bacteria is much rarer, but is also more severe. The most common bacterial pathogens include salmonella, campylobacter, shigella, yersinia and the intestinal bacterium Escherichia coli. Infection by parasites usually occurs when traveling to countries with low hygiene standards. These are mainly countries in Africa, Central America and South Asia.
Gastroenteritis is usually transmitted by smear infection. Just 10 to 100 virus particles are enough to cause infection. If pathogens from stool and vomit get onto objects and surfaces, the pathogens can enter the mouth and digestive tract of other people via contact with the hands. This is referred to as fecal-oral transmission, fecal being the term for bowel movements, oral for via the mouth.
Occasionally it also occurs through droplet infection, where tiny particles of vomit spread through the air.
When traveling abroad, people usually become infected through contaminated drinking water or contaminated food. This is particularly the case in less developed countries, e.g. in parts of Africa or Asia. Poor hygiene conditions are a particularly common cause of gastrointestinal infections there.
Can antibiotics also cause gastroenteritis?
Taking antibiotics is also a typical cause of diarrhea. The reason for this is that antibiotics can damage the normal intestinal flora and thus lead to increased growth of pathogenic germs. These in turn can produce toxins and release them into the intestine (so-called exotoxins) or act as toxins themselves (so-called endotoxins). These toxins and the pathogenic bacteria can be detected in stool samples. The only sensible measure in such cases is to discontinue the antibiotic so that the intestinal flora can recover and rebuild.
Depending on the pathogen, symptoms can range from very mild to severe. The most common and prominent symptom is diarrhea, which can be watery, especially in the case of a viral infection.
The symptoms of gastroenteritis usually start suddenly. The incubation period, i.e. the time between infection and the onset of symptoms, is between 4 and 48 hours. Typical symptoms associated with gastroenteritis are
Depending on the type of pathogen, other symptoms may also occur, for example
How long does gastroenteritis usually last?
The symptoms usually subside after 24 to 48 hours. If the symptoms do not improve after 48 hours, you should definitely consult a specialist. Gastroenteritis should not be taken lightly, as vomiting and diarrhea lead to a loss of fluids, electrolytes and nutrients.
In most cases, gastroenteritis can be diagnosed by taking a medical history and performing a physical examination. Other measures or complex imaging procedures are rarely necessary. A stool sample may be indicated to detect pathogens, especially if there is a suspicion of antibiotic-associated (caused by antibiotics) gastroenteritis.
What is important in the medical history?
Taking a medicalhistory is extremely important. This includes in particular asking about
- previous history,
- medication taken or
- special events leading to the illness.
Among other things, a stay abroad or contact with sick people are important here and must be asked about. However, the intake of special medication or suspected food intolerances should also be asked and mentioned here. In addition, questions are typically asked about the nature of the stool, the frequency and any additional blood deposits.
What is included in the physical examination?
In addition to the medical history, the physical examination is another very important and often groundbreaking diagnostic measure. The abdomen is palpated, and in particular it is examined whether there are any pressure points or localized pressure pain in the abdomen. Resistance, i.e. palpable hardening, can also be detected during the physical examination.
A stethoscope can be used to listen to the bowel sounds. The suspicion of constrictions can already be expressed here without further measures or imaging by experienced doctors.
The skin and the condition of the skin are also assessed. Dry skin and so-called "standing skin folds" are important indications of increased fluid loss, which can amount to several liters per day in the case of severe diarrhea. The loss of fluid results in reduced elasticity of the connective tissue, which is the cause of the standing skin folds. As soon as the fluid balance is normalized, the skin usually regains its original elasticity.
When are further examinations necessary?
In certain cases, further examinations are necessary, including in the following situations:
- in infants under 3 months of age
- blood in the stool
- after a stay abroad in risk areas
- in the case of a severe and long course of illness
- in the case of immunodeficiency such as AIDS
- if important concomitant diseases are present
- if the patient works in communal facilities or processes food
- if the patient is planning to take or has recently taken antibiotics
Further examinations include blood, urine and stool tests and, in rare cases, an endoscopy (colonoscopy) or ultrasound.
The majority of those affected are treated without medication; antibiotics should be discontinued if possible. The most important thing in the case of gastroenteritis is sufficient fluid intake. Patients should drink plenty of fluids (especially water and unsweetened tea) to compensate for fluid loss. Electrolyte powders can also be prescribed for infants, small children and older people; magnesium, calcium and potassium in particular can cause deficiency symptoms and should be replaced quickly. In cases of severe fluid loss, hospitalization and infusion therapy may also be necessary.
In addition, those affected should try to eat light foods such as rusks, soups, bananas, carrots or oatmeal. Occasionally, medication is also prescribed to inhibit vomiting or bowel movements. In certain cases, treatment with antibiotics is necessary. This is useful, for example, in the case of severe courses of the disease, premature babies, older people, bloody diarrhea and bacterial pathogens such as salmonella, shigella or Escherichia coli.
As a rule, gastroenteritis is harmless and passes after just a few days. However, there are certain risk groups in which the course of the disease can be severe and in extreme cases even life-threatening. These include newborns, small children and older people who lose fluids and electrolytes due to severe and frequent vomiting. Closer monitoring is also advisable during pregnancy and breastfeeding to avoid complications for mother and child.
