Updated: October 2026
In short: With diarrhoea, fluids help most: drink water, unsweetened tea or broth spread over the day, and with heavy loss an electrolyte solution from the pharmacy. You can eat as soon as you have an appetite again, ideally light and not too fatty. With blood in the stool, high fever, severe abdominal pain or if the diarrhoea doesn't get better after a few days, it should be checked by a doctor. As of: October 2026.
Diarrhoea is annoying but usually harmless and over after a few days. It becomes dangerous mainly through fluid loss. Here's what you can do yourself and where the line to a doctor's visit lies.
Where does diarrhoea come from in the first place?
The most common cause is stomach and gut infections and spoiled food. According to the NHS, medication, food intolerances, irritable bowel syndrome, anxiety and stress, and chronic bowel diseases such as Crohn's disease or coeliac disease are also possible triggers. For acute diarrhoea, the NIDDK mainly names viruses such as norovirus and rotavirus.
Important for context: a single loose stool isn't diarrhoea yet. Diarrhoea means frequent, watery stools. How to classify your stool is covered in the article Bowel Movements: What Is Normal?. Recurring complaints can also belong to an irritable bowel that only a doctor can diagnose.
What matters most with diarrhoea: drinking?
Yes. With diarrhoea, you lose water and electrolytes, that is minerals such as sodium and potassium. The NIDDK writes that you need to replace lost fluid and electrolytes so you don't dehydrate. It names water, broth and electrolyte solutions.
The NHS advises taking small sips at first if you feel nauseous, and points to electrolyte powder from the pharmacy that you dissolve in water. Get advice there, especially for children, older people and pregnant women.
- Small amounts, but often: a sip every few minutes is better than one big glass at once.
- Well suited: water, unsweetened herbal tea, clear broth.
- Electrolyte solution from the pharmacy for frequent, watery stools.
According to the NIDDK, you recognise dehydration by strong thirst or a dry mouth, less frequent trips to the toilet, tiredness and dark urine. If you bring everything back up despite small sips, that's a reason to check with a doctor.
More on the basics is in Fluid Balance: The True Importance for the Body.
What can you eat with diarrhoea?
What you have an appetite for, in small, light portions. The NHS advises: eat if you feel able to, and avoid rather fatty and spicy food. The NIDDK writes that most people can return to their normal diet as soon as their appetite is back.
You don't need a rigid bland-diet scheme. In practice, simple food your tummy knows well works:
- Rice, potatoes, pasta, porridge
- Banana, cooked carrots, rusks or toast
- Clear vegetable broth or a mild soup
For prevention, the NIDDK names thorough hand washing (at least 20 seconds) and clean handling of food. That also protects others in the household if an infection is the cause.
If you're not hungry, that's fine in the first day or two, as long as you drink.
What should you avoid with diarrhoea?
Above all, avoid drinks that can make diarrhoea worse. The NHS explicitly names fruit juice and fizzy drinks. Fatty and spicy food also tends to strain the gut.
| Better to avoid | Why |
|---|---|
| Fruit juice, lemonade, soft drinks | According to the NHS they can make diarrhoea worse |
| Fatty, fried, very spicy food | The NHS advises avoiding such dishes |
| Alcohol | Withdraws fluid, adds strain (general note) |
| High-fibre raw vegetables, large portions | Often harder to tolerate with a sensitive gut, build back up later |
Our cold-pressed juices also fall into the fruit juice category: wait with them until your stool has normalised.
How long does diarrhoea last, and when should you see a doctor?
Acute diarrhoea usually passes in a few days. The NHS gives typically 5 to 7 days for adults. From when you should seek medical advice, the sources assess differently: the NHS says more than 7 days, MedlinePlus more than 5 days for adults, the NIDDK more than 2 days.
A practical rule of thumb from this range: if it doesn't get better after about two days, call the practice. You need medical help immediately with these warning signs:
- Black, tarry stool or red blood or pus in the stool (NIDDK, NHS)
- Severe abdominal pain
- High fever (MedlinePlus gives over 38.3 degrees, so 101 degrees Fahrenheit)
- Six or more loose stools per day (NIDDK)
- Signs of dehydration: strong thirst, dry mouth, little and dark urine, weakness
For infants and small children, pregnant women, older people and people with pre-existing conditions: better to ask earlier.
Mild or get it checked: how do you classify diarrhoea?
This table summarises the notes from the sources opened. The table doesn't replace a medical assessment.
| Rather mild, observe | Get it checked by a doctor |
|---|---|
| Watery stool for 1 to 2 days, you can drink | No improvement after about 2 days or longer than 5 to 7 days |
| Mild abdominal cramps, no high fever | Fever above 38.3 degrees, severe pain |
| Stool without visible blood | Blood, pus or black, tarry stool |
| Normal urine, no strong thirst | Dark urine, hardly any urine, strong thirst, dizziness |
| Improving after an infection or a meal | Recurring or over weeks, with no clear cause |
If symptoms last longer, weight loss with no apparent reason is also a reason for a visit to the doctor's practice.
How do you build the gut back up afterwards?
Slowly. Only when the stool becomes firmer again do higher-fibre foods return. How to do that step by step is in High-Fibre Foods. If afterwards you tend more towards hard stools, you'll find help in Constipation: What Helps, and for bloating in Bloated Belly: What Helps.
A good overview of all digestive topics is given by the Gut and Digestion Guide, and prompts for a generally sluggish gut in Stimulating Digestion. We cover antibiotics as a trigger in Gut Restoration After Antibiotics.
Pairs well with frank.
When your tummy is calm again, many people like to drink mild tea. Our Happy Stomach Tea (organic, loose, with fennel, aniseed, chamomile and ginger, from 15 EUR) can be a pleasant companion in everyday life. It is not a remedy for diarrhoea.
You might also like
- Frank Gut Basics: What You Need to Know!
- What Is Healthy for the Gut - 7 Tips for Your Gut Health
- Fluid Balance - The True Importance for the Body
Frequently asked questions about diarrhoea
What helps fastest with diarrhoea?
Drinking enough. Diarrhoea usually passes on its own, but the loss of fluid and electrolytes is the risk. Drink water, tea or broth in small sips, and with heavy loss an electrolyte solution from the pharmacy.
Can I drink cola or fruit juice with diarrhoea?
The NHS advises against fruit juice and fizzy drinks because they can make diarrhoea worse. Better are water, tea and broth or an electrolyte solution from the pharmacy.
Should I go hungry with diarrhoea?
No, but you don't have to eat. Eat when you have an appetite, light and not too fatty. More important than eating in the first days is drinking.
How long can diarrhoea last?
In adults, acute diarrhoea usually passes in 5 to 7 days (NHS). The sources give a limit for seeing a doctor of between 2 and 7 days. If it doesn't get better after about two days or warning signs appear, ask at the practice.
What signs mean I need to see a doctor immediately?
Blood or pus in the stool, black tarry stool, severe abdominal pain, high fever and signs of dehydration such as strong thirst, dark urine and weakness.
Do probiotics help with diarrhoea?
There is no blanket recommendation for supplements from the sources opened. If needed, talk to your doctor or at the pharmacy. After the diarrhoea, you can support the gut with a high-fibre diet.
Note: This article is for general information and does not replace medical or therapeutic advice. If you have symptoms or pre-existing conditions, are pregnant or take medication, please speak to your doctor first.
