Written by
Læge
Praktiserende læge, ph.d.
Stomach flu, caused by a virus, is the most common cause of diarrhoea and vomiting. Infections with Salmonella and Campylobacter, however, are becoming increasingly common. It is important to heat-treat your food sufficiently. You should drink plenty of fluids with salt and sugar.
When you have more than 10 thin stools a day, you have diarrhoea. Vomiting and diarrhoea are often caused by a gastrointestinal infection caused by a virus (stomach flu) or, more rarely, bacteria.
In connection with the vomiting, there may be periodic stomach pain and a slightly elevated temperature. Typically, more people in your family or circle of acquaintances are ill. Most cases resolve on their own within 36 hours.
Several different bacteria can cause a gastrointestinal infection. Two of the most common bacteria are Salmonella and Campylobacter. Most often, people are infected with other, rarer bacteria while travelling abroad.
Gastrointestinal infection with Salmonella begins suddenly with nausea, watery, slimy stools, vomiting, and intermittent stomach pain. The temperature may rise to 39-40ºC and disappear again after a couple of days.
Gastrointestinal infection with Campylobacter begins with queasiness for a couple of days. Hereafter, diarrhoea containing blood, light fever, and very heavy stomach pains. Today, Campylobacter is the most common cause of fever and bloody diarrhoea.
Salmonella and Campylobacter are found in domestic animals, including poultry, pigs, and calves. Meat that has not been sufficiently heat-treated can transmit Salmonella and Campylobacter to people. The risk is particularly high with eggs. Often, eggs are an ingredient in dishes that are not heat-treated, like buttermilk koldskål, mayonnaise, and vanilla cream. Salmonella and Campylobacter cannot be seen, smelled, or tasted in food. Both bacteria are avoidable if you heat-treat your food sufficiently.
Your doctor can, by examining your stool, find out whether it is a virus, Salmonella, or Campylobacter causing the diarrhoea. In most cases of Salmonella or Campylobacter infection, the infection resolves on its own within a couple of days.
A gastrointestinal infection caused by a virus is highly contagious. The illness is transmitted from person to person by direct contact. Gastrointestinal infections caused by Salmonella or Campylobacter are practically not transmitted from person to person. Transmission of the disease occurs when eating food that has not been sufficiently heat-treated.
When can I go to work?
When you are free of fever, and the stool is becoming normal.
Most cases of Salmonella or Campylobacter in the stool should not be treated with antibiotics and should resolve over a couple of days. In the case of prolonged diarrhoea, antibiotic treatment may be an option. Possibly, the doctor will take stool samples for closer examination.
If you have diarrhoea, vomiting, and fever at the same time, you lose a lot of fluid. This can lead to drowsiness and the urge to sleep the whole time. Therefore, you must have plenty to drink, preferably drinks that contain salts and calories (for example, tea with sugar, fizzy drinks, or sweet lemonade). Avoid coarse and fibre-rich foods while the stool remains thin. This only irritates the intestines, causing the diarrhoea to continue.
If you vomit for more than 48 hours, have diarrhoea and fever, or if there is blood in the stool.
If you have persistent stomach pains. If you have become drowsy, cannot drink, and prefer sleeping.
