Quick answer: With short-term diarrhoea, the priority is fluids and salts: water plus an oral rehydration solution from the pharmacy. Keep eating small, simple meals such as rice, potatoes, bananas, toast, soups, cooked carrots and eggs, and go easy on alcohol, very fatty food, sugary drinks and sugar-free sweets. Most episodes settle within days. If loose stools, urgency, pain or bloating carry on for weeks after a stomach bug, this may be post-infectious IBS, which follows around 1 in 10 gut infections. Persistent diarrhoea should always be checked by your doctor.
Diarrhoea is one of the most searched gut symptoms, usually in a hurry. This article covers both sides: what to eat in the first days, and what may be happening if things never quite go back to normal. If your symptoms started after a course of antibiotics, see how to support your gut after antibiotics.
What should I eat when I have diarrhoea?
The old advice to stop eating is outdated. Your gut lining needs fuel to recover, and small amounts of simple food are usually better than nothing. Foods many people tolerate well in the first days:
- White rice, rice soup or congee
- Boiled or mashed potatoes, without much butter
- Ripe bananas, which provide potassium
- Toast, plain crackers or oat porridge made with water
- Clear soups and broths, which add salt and fluid
- Cooked carrots, courgette or pumpkin
- Eggs, white fish or chicken, cooked simply
- Plain yoghurt, if dairy usually suits you
A very restrictive “bananas, rice, apple and toast only” diet is not necessary for more than a day or two. Bring back your usual foods step by step as stools firm up.
What should I avoid with diarrhoea?
- Alcohol and large amounts of coffee
- Very fatty, fried or rich meals
- Sugary drinks and undiluted fruit juice, which can pull water into the gut
- Sugar-free sweets and gum containing sorbitol, mannitol or xylitol
- Large glasses of milk, as lactose can be harder to digest for a few days
- Lots of raw vegetables, pulses and bran until things settle
What should I drink?
Fluids matter more than food. Sip water regularly and use an oral rehydration solution (sachets from the pharmacy) if diarrhoea is frequent, as it replaces salts as well as water in the right balance. Sports drinks and fizzy drinks are not good substitutes. Weak tea and broth are fine alongside.
When to see your doctor first
- Blood in the stool, or black, tarry stools
- Signs of dehydration: very little urine, dizziness, confusion or a dry mouth (seek urgent care)
- High fever or severe, constant abdominal pain
- Diarrhoea lasting more than 7 days, or waking you at night
- Diarrhoea after recent antibiotics or a hospital stay, or after travel abroad
- Unintended weight loss, or diarrhoea in older adults, during pregnancy or with a weakened immune system
Why do I still have gut symptoms weeks after food poisoning?
Most people recover fully. But in a meta-analysis of more than 21,000 people, around 10% developed irritable bowel syndrome after an episode of infectious gastroenteritis, and the risk was higher after more severe infections.1 This is called post-infectious IBS. It usually looks like diarrhoea-predominant or mixed IBS: urgency, loose stools, cramping and bloating.
The infection is gone, but it can leave behind a more sensitive, more reactive gut. Researchers describe changes such as low-grade immune activation in the gut lining, a shift in the microbiome, altered bile acid handling and increased gut permeability.2 One line of research has looked at a toxin produced by some food-poisoning bacteria, and antibodies that may affect the nerves that control gut movement.4 Slower “cleaning waves” in the small intestine are one reason post-infectious IBS and SIBO often appear together. Read more in SIBO: root causes and symptoms.
Who is more likely to get post-infectious IBS?
Risk appears higher in women, in people who had a more severe or longer infection, in those who were anxious or under significant stress at the time, and after bacterial or parasitic infections.1 It is not a sign that you did anything wrong.
Does post-infectious IBS go away?
For many people it improves gradually. A long-term follow-up after a large waterborne outbreak found that symptoms eased for a significant proportion over the years, although for some they persisted.3 Support can make that recovery easier.
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Book your free 15-minute call →When should ongoing diarrhoea be investigated?
Diarrhoea that lasts longer than four weeks is considered chronic and should be looked at by your doctor. UK guidelines suggest checks such as coeliac blood tests, faecal calprotectin and, where relevant, tests for bile acid diarrhoea, before IBS is assumed.5 See faecal calprotectin explained.
How can nutritional therapy help?
Nutritional therapy does not replace your doctor’s assessment or medical care. Once other causes have been looked at, it can help map your triggers, rebuild a varied diet step by step, and look at meal rhythm, stress and the gut-brain connection, working alongside your medical care. Any supplements, such as particular probiotics, are optional and chosen individually.
Frequently asked questions
How long does diarrhoea from food poisoning last?
Most episodes settle within a few days and usually within a week. Diarrhoea lasting longer than a week, or with any warning signs, should be checked by your doctor.
Is the BRAT diet good for diarrhoea?
Bananas, rice, apple sauce and toast are gentle, but the diet is too limited to follow for more than a day or two. It is better to add other simple foods, such as potatoes, soups, eggs and cooked vegetables, as soon as you feel able.
Should I take a probiotic for diarrhoea?
Some specific strains have evidence for certain types of diarrhoea, but results vary by strain and situation. It is worth asking your doctor or pharmacist, especially if you are unwell or have a weakened immune system.
Can food poisoning cause IBS?
Yes. Around 1 in 10 people develop IBS-type symptoms after a gut infection. This is called post-infectious IBS and it often improves gradually.
Can I drink coffee with diarrhoea?
Coffee stimulates the bowel, so many people feel better avoiding it or keeping it small until stools firm up.
References
- Klem F, et al. Prevalence, Risk Factors, and Outcomes of Irritable Bowel Syndrome After Infectious Enteritis: A Systematic Review and Meta-analysis. Gastroenterology. 2017. PubMed: PMID 28069350
- Barbara G, et al. Rome Foundation Working Team Report on Post-Infection Irritable Bowel Syndrome. Gastroenterology. 2019. PubMed: PMID 30009817
- Marshall JK, et al. Eight year prognosis of postinfectious irritable bowel syndrome following waterborne bacterial dysentery. Gut. 2010. PubMed: PMID 20427395
- Pimentel M, et al. Development and validation of a biomarker for diarrhea-predominant irritable bowel syndrome in human subjects. PLoS One. 2015. PubMed: PMID 25970536
- Arasaradnam RP, et al. Guidelines for the investigation of chronic diarrhoea in adults: British Society of Gastroenterology, 3rd edition. Gut. 2018. PubMed: PMID 29653941
This article is for educational purposes and is not medical advice. Nutritional therapy does not replace medical care. Always work with your doctor for any persistent or new symptoms and before making changes to your care, medication or supplements.