Diarrhoea
What causes diarrhoea?
There are many reasons why you might have diarrhoea, and managing it often depends on identifying the cause. Diarrhoea can happen due to infections, medications, underlying conditions or in some cases, be a side effect of treatments. Common causes include:
Emotions
Emotional factors similar to feelings of anxiousness or everyday stress can sometimes trigger diarrhoea.
Side effects of medication
Certain medications, such as antibiotics and laxatives, may cause diarrhoea.
Underlying health conditions
Conditions such as irritable bowel syndrome (IBS), coeliac disease, or diverticular disease may cause diarrhoea.
Infections
These could be caused by viruses (e.g. norovirus, rotavirus), bacteria (e.g. E. coli from contaminated food), or parasites. Infections may also occur while travelling, known as travellers’ diarrhoea.
Your doctor may request a stool sample to check for infections. Understanding the cause of diarrhoea can help manage it effectively.
Food intolerance or allergy
Sensitivity to specific foods can cause digestive issues. It may be worth keeping a diary of your eating habits to track and identify any food intolerance triggers for diarrhoea.
Managing & treating diarrhoea
Most cases of diarrhoea clear up on their own within a few days without the need for medical treatment. However, there are some self-care steps and treatments that can help ease symptoms and support your recovery.
Antibiotics
For travellers or people who have severe diarrhoea, a doctor may prescribe antibiotics, depending on the cause. However, diarrhoea can sometimes be a side effect of antibiotics, which usually resolves after the course finishes. If this carries on, make sure to speak with your doctor.
Most cases of diarrhoea improve on their own. If symptoms are severe, or if you’re concerned, make sure to speak to a pharmacist or your GP.
A pharmacist can support you if:
- You or your child (over 5) have signs of dehydration, like dark or strong-smelling pee, or are peeing less than usual
- You’re older, have a weakened immune system, or have a health condition that makes you more at risk of dehydration
- You’re looking for quick relief from diarrhoea for a few hours
Medication
Over-the-counter anti-diarrhoea medication, like loperamide, can help reduce how much you’ll be using the toilet.
This is typically suitable for adults but shouldn’t be given to children under 12. Make sure to always read the patient information leaflet of any medication you’re taking.
Pain relief medicines
If you’re in discomfort, you can take pain relief medicines to help with this. Make sure to always check it’s suitable for your child or baby. Children under 16 shouldn’t be given aspirin. It’s important to read the patient information leaflet for any medication you or your child will be taking.
Staying hydrated is important, especially during diarrhoea, as your body can lose fluids and salts.
Replacing these is particularly important for:
- Babies and young children
- Older adults
For these groups, rehydration solutions (oral rehydration powders that can be mixed with water to make a drink) can help. They’re usually available over the counter at pharmacies. You can speak to a pharmacist for more advice on rehydration solutions.
Adults can generally rehydrate by drinking more fluids, like water or diluted squash. Foods with high water content like soup can also help with rehydration.
You don’t need to stop eating if you have diarrhoea, but a lighter diet may feel more comfortable at first.
Adults may benefit from smaller, frequent meals. Chewing slowly and relaxing after eating can also be helpful. Try choosing soft, easy-to-digest foods like:
- White fish
- Mashed potatoes
- Yoghurt
- Milk puddings
- Sorbet
Lower fibre options like white bread and plain biscuits may be gentler on the stomach.
Some foods may make diarrhoea worse or cause additional cramps and gas, so it’s important to avoid:
- High-fibre foods like wholemeal bread, brown rice and wholegrain cereals
- Uncooked fruits and vegetables
- Foods like nuts, dried fruit, beans, cauliflower, cabbage and onions
- Spicy, fried, or fatty foods, including curries, cream and chips
- Very hot or very cold foods and drinks
- Alcohol, fruit juice, fizzy drinks, strong tea and coffee
Once you start feeling better, you can gradually reintroduce your usual diet.
Diarrhoea in children & babies
Diarrhoea is common in children and babies and is usually caused by an infection. While it can be unsettling to see your little one unwell, most cases improve on their own with rest, fluids and a bit of time. Keeping your child hydrated and comfortable is key.
Babies and young children are more at risk of dehydration, so it’s important to seek medical help if your baby or child has any signs of dehydration.
For small children, continue regular feeding. For breastfed babies, keep breastfeeding as usual. For bottle-fed babies, stick to their usual-strength formula, it’s important to not make it weaker. For more advice on managing diarrhoea in children, visit our guide on diarrhoea in children, toddlers and babies.
When do I need to see a doctor about diarrhoea?
Most cases of diarrhoea resolve on their own with rest and fluid. However, there are times when it’s important to speak to your GP or call NHS 111.
Make sure to call 999 or go to A&E if you or your child:
- Is vomiting blood or vomit looks like ground coffee
- Have green vomit (adults), yellow-green or green vomit (children)
- May have swallowed something poisonous
- Have a stiff neck and find bright lights painful
- Have a sudden, severe headache or tummy ache
- Show blue, grey, pale, or blotchy skin, lips, or tongue, on brown or black skin, this may show on the palms or soles
- Are struggling to breathe or taking rapid, shallow breaths
- Are confused or not responding normally
Make sure not to drive yourself to A&E. You should ask someone to take you or call for an ambulance. Make sure to bring any medications you’re taking with you.
Most of the time, diarrhoea improves without medical attention, but it’s important to know when to reach out if symptoms don’t settle.
Make sure to call NHS 111 for advice if:
- You’re concerned about a baby under 12 months
- Your child has stopped breast or bottle feeding while unwell
- A child under 5 shows signs of dehydration, like fewer wet nappies
- You or your child (over 5) still have dehydration signs after using oral rehydration sachets
- You or your child are continuously being sick and can’t keep fluids down
- You or your child have bloody diarrhoea or bleeding from the bottom
- Diarrhoea has lasted more than 7 days, or vomiting has lasted more than 2 days
NHS 111 can guide you on the next steps and arrange a call with a nurse or doctor if needed.
How do I help prevent diarrhoea?
Diarrhoea is highly contagious, making it essential to refrain from attending school or work until you have been symptom-free for at least 48 hours.
When travelling, it’s crucial to avoid unsafe tap water and undercooked food to reduce the risk of contracting this condition.
By taking these precautions, you can help protect yourself and others from the spread of diarrhoea.
To help prevent spreading the infection, make sure to:
- Wash your hands frequently with soap and water
- Wash any clothing or bedding that has been soiled separately on a hot wash
- Clean toilets and surfaces, including seats, flush handles, taps and door handles, every day
- Avoid preparing food for others if possible
- Avoid sharing towels, flannels, cutlery or utensils with others
- Avoid swimming pools for at least 48 hours after symptoms have stopped
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Frequently asked questions
Diarrhoea doesn’t usually cause weight loss, but it can lead to weight loss if it’s severe, chronic or not treated. If you have diarrhoea and you’re experiencing weight loss, make sure to speak to your GP.
Diarrhoea can sometimes be linked to back pain, as cramps or digestive discomfort may cause mild lower back aches. This usually eases as symptoms improve. However, if the back pain is severe, persistent or comes with other symptoms like fever, it’s important to speak to your GP.
To help provide quick relief from diarrhoea, a pharmacist can advise on over-the-counter medications like anti-diarrhoeal tablets, which can help to treat short-term diarrhoea.
A pharmacist can also advise you on oral rehydration solutions which don’t stop the diarrhoea itself, but help to provide a good balance of salts, water and sugar. These can help to replace lost water and body salts.
When it comes to food, stick to soft, easily digested foods like white fish, mashed potatoes, ice creams and yoghurt.
If symptoms persist beyond a few days or worsen, it’s important to see a GP.
While there aren’t foods that will immediately stop diarrhoea, there are foods that can help manage symptoms when you have diarrhoea.
A short-term diet of bland, ‘lower’ fibre varieties of food like white bread, white pasta and milk puddings can be helpful.
Try to avoid spicy, fried, or high-fibre foods, like wholemeal bread, wholegrain cereals, brown pasta and rice and fruit juice, which can irritate the digestive system.
Yes, you can still eat if you have diarrhoea. We’ve covered more on this in the ‘Managing diarrhoea’ section of the page. Eating small amounts can help keep your energy up and support your recovery.
Bile acid diarrhoea happens when bile acids aren’t fully reabsorbed into the bloodstream and instead enter the large bowel (colon). This makes extra water and salts move into the bowel, leading to watery diarrhoea.
This condition is also known as bile acid malabsorption, as it’s caused by the body losing water and salts into the bowel rather than reabsorbing them.
It can be caused by some health conditions which affect the gut like:
- Coeliac disease
- Chronic pancreatitis
- Small bowel bacterial overgrowth
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