Stomach bug and sick note in Germany: how long to stay home, what helps, what works by video

Stomach bug: what is behind it and how long it lasts

An acute stomach bug, medically gastroenteritis, is an inflammation of the lining of the stomach and intestine, usually caused by viruses. In adults noroviruses are the most common cause, in children rotaviruses; less often bacteria such as Campylobacter or Salmonella are responsible, especially after food or travel. Infection occurs via tiny amounts of stool or vomit, via hands, surfaces and food, and with norovirus also via droplets when vomiting.

The course is typical for norovirus: six to fifty hours after infection it starts suddenly with nausea, projectile vomiting and watery diarrhoea, often with abdominal cramps, headache and mild fever. After twelve to 48 hours the worst is over. Usually a day of weakness and a sensitive stomach remains. Bacterial infections often last longer, come with higher fever and can cause bloody diarrhoea.

Important for infectivity: noroviruses are still shed for days to two weeks after symptoms subside, in large quantities during the first 48 hours. So the point at which you no longer infect others is not the end of symptoms but two days later.

How long signed off? Reference values and occupational rules

You are unfit for work as long as vomiting, diarrhoea, circulatory weakness or cramps make work impossible and as long as you would infect others. That is usually two to four days. For certain occupations statutory rules apply in addition.

Situation	Usual duration of incapacity	Basis
Office, home office, trades without food contact	2 to 3 days	medical assessment
Food processing, kitchen, hospitality, sale of unpackaged food	until 48 hours after the last symptoms, often 3 to 4 days	section 42 IfSG, RKI recommendation
Care, nursery, school, community facilities	until 48 hours after the last symptoms	section 34 IfSG, RKI recommendation
Bacterial infection with fever or bloody diarrhoea	after examination, often longer	practice

Section 42 of the Infection Protection Act (Infektionsschutzgesetz, IfSG) prohibits people with infectious gastroenteritis from producing, handling or marketing food and from working in kitchens of community facilities. For norovirus the Robert Koch Institute recommends returning no earlier than 48 hours after symptoms subside and paying particular attention to hand hygiene for four to six weeks afterwards. If you work in such an occupation, say so in the video consultation; the doctor takes it into account when setting the duration.

By video, OpenClinic24 issues the private certificate usually from the day of the consultation for at most three calendar days, backdated only exceptionally after medical assessment and not extendable by video. If symptoms last longer, reassessment belongs in a practice, which can then also arrange a stool sample.

Why a stomach bug can be assessed well by video

To assess uncomplicated gastroenteritis the doctor mainly needs your account: onset, frequency of vomiting and diarrhoea, fever, blood in stool, abdominal pain and its location, fluid and urine output, travel, contacts with the same symptoms, pre-existing conditions and medication. Then the look at you: do you appear dehydrated, pale, weak? All of this works by video. With a typical course without warning signs, a physical examination rarely changes the treatment, which consists of fluids and rest anyway.

The second reason is infection control: one person with norovirus in a waiting room can infect an entire practice. The video consultation keeps you at home and protects others.

Where video reaches its limits, the doctor refers you on: with blood in stool, high fever, severe or one-sided abdominal pain, signs of dehydration, symptoms beyond three days, after tropical travel, in pregnancy, in infants, older people and immunocompromised people. Then examination, laboratory tests or a stool sample are needed, and with severe courses an infusion.

What helps: fluids first, then food

The most important treatment is replacing fluids and salts. Drink two to three litres a day in small sips, even if you feel nauseous: water, diluted juice, herbal tea, clear broth. With greater loss, meaning frequent vomiting or more than six watery stools a day, an oral rehydration solution from the pharmacy is useful; it contains glucose and salts in the right ratio according to the World Health Organization formula. Cola and pretzel sticks are no substitute because cola contains too much sugar and too little sodium.

Eat as soon as you have an appetite and start with easily digestible food: rusks, white bread, rice, potatoes, porridge, banana, grated apple. Fatty, heavily spiced food, alcohol and coffee can wait until the gut has settled. A strict diet is not necessary according to the guidelines; eating again early tends to shorten the course.

Medicines play a minor role. An anti-nausea medicine can help if you otherwise keep nothing down; loperamide can reduce stool frequency for watery diarrhoea without fever and without blood for a journey or an appointment, but should not be used for longer than two days or with fever or bloody stool. Antibiotics do not help with viral infections and, according to the guideline, are only indicated for certain bacterial infections with a severe course diagnosed in a practice. Probiotics may slightly shorten the duration; the evidence is mixed.

Protecting others: hygiene at home

Wash your hands with soap after every visit to the toilet and before every meal; water and soap remove noroviruses mechanically better than most disinfectants. Use your own towels and if possible your own toilet; clean toilet, flush, door handles and basin daily. Wash laundry with vomit or stool at 60 °C or more. Do not prepare food for others while you have symptoms and for 48 hours afterwards. Alcohol-based hand sanitisers only work against norovirus if labelled virucidal.

When to go to a practice, when to call emergency services

You belong in a practice if symptoms last longer than three days, with fever above 39 °C, after long-haul travel, in pregnancy, with chronic bowel disease, in infants and small children, over 65, with immunodeficiency or if you take medicines whose effect is jeopardised by vomiting and diarrhoea, such as anticoagulants, diabetes medication or the pill. There a stool sample, laboratory tests and, if needed, an infusion can be arranged.

Call 112 for blood in stool or vomit, severe dehydration with confusion or circulatory weakness, severe abdominal pain with a rigid abdomen and fever with a stiff neck. In infants and very old people every hour counts because fluid loss quickly becomes dangerous.

Checklist for the first days

Notify your employer on the first day. Submit the request for the video consultation the same day, even at the weekend. Mention a job with food contact or in a community facility in the consultation. Drink in small sips, rehydration solution with greater loss. Eat as soon as you have an appetite. Wash hands, use your own towel, clean the toilet. Return no earlier than 48 hours after the last symptoms if your job requires it. With warning signs or symptoms beyond three days, go to a practice or the on-call service.

As of October 2026.