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Written by Dr. Simon Khela MBChB MRCGP, GMC Registered Doctor
Last reviewed: 28-07-2026
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Diarrhea in the UK is common and usually clears within a few days. However, it can sometimes lead to dehydration or indicate an infection, medication side effect, food intolerance, or longer-term digestive condition.
The most important steps are to replace lost fluids, monitor your symptoms, and recognise the warning signs that require medical attention.
Concerned about persistent or severe symptoms? A Private GP consultation can help identify the cause and determine whether you need tests, medication, or specialist care.
Diarrhea is the frequent passage of loose or watery stools. It may also cause urgency, abdominal cramps, bloating, nausea, or vomiting.
Doctors often describe diarrhea according to how long it lasts:
Acute diarrhea is commonly caused by an infection and often settles without specific treatment. Persistent or recurring symptoms require medical assessment because they may be linked to an underlying digestive condition.
Diarrhea can have many causes. Some begin suddenly, while others develop gradually or return repeatedly.
Viruses such as norovirus are a common cause of sudden diarrhea and vomiting. These infections spread easily through contaminated food, surfaces, or close contact.
For more information about symptoms, transmission, and recovery, read our guide to norovirus.
Bacteria such as Salmonella, Campylobacter, and certain types of E. coli can cause diarrhea after contaminated food or water is consumed.
Symptoms may include:
Traveller’s diarrhea may occur after consuming contaminated food or water abroad. Risk can be reduced by drinking safe water, practising careful food hygiene, and seeking health advice before travel.
Patients planning an overseas trip can review our travel vaccination services and guidance on staying healthy while travelling.
Some people develop diarrhea because they cannot fully digest certain foods or ingredients. Possible triggers include:
Coeliac disease can cause diarrhea, bloating, fatigue, weight loss, and nutritional deficiencies. Learn more in our guide to coeliac disease symptoms and causes.
Several medicines can cause diarrhea as a side effect, including:
Do not stop prescribed medication without speaking to a clinician. A GP can review your medicines and advise whether the dose or treatment needs to change. Private prescriptions may also be arranged when clinically appropriate through our private prescription service.
The gut and brain communicate closely, so stress can affect bowel habits. Some people experience diarrhea before an exam, journey, presentation, or stressful event.
When anxiety repeatedly affects digestion, support such as cognitive behavioural therapy or depression and anxiety treatment may help alongside a medical assessment.
Recurring or chronic diarrhea may be associated with:
Diarrhea alone does not mean you have a serious condition. However, unexplained changes in bowel habits should be assessed, particularly when they occur with bleeding, weight loss, anaemia, or persistent pain.
Read more about bowel cancer in younger adults and the importance of appropriate cancer screening.
Diarrhea may occur on its own or alongside:
The combination of symptoms can help a doctor identify the likely cause.
Frequent watery stools cause the body to lose water and electrolytes. If these losses are not replaced, dehydration can develop.
Watch for:
Children can become dehydrated more quickly than adults. Warning signs include:
Older adults, babies, pregnant women, and people with long-term health conditions may be more vulnerable to complications.
Most mild cases can be managed at home, provided there are no warning signs.
Drink small amounts frequently, especially if nausea is present. Suitable options include:
Oral rehydration solutions are particularly useful because they replace both water and essential salts.
Avoid drinking large amounts of alcohol, highly caffeinated drinks, or very sugary beverages because they may worsen symptoms or dehydration.
You do not usually need to avoid food completely. Begin with small, simple meals and return gradually to your normal diet.
Foods that may be easier to tolerate include:
A restrictive diet is not always necessary, and prolonged fasting may slow recovery.
For broader nutrition advice, see our guide to healthy eating.
Your body may need additional rest while recovering from an infection. Avoid strenuous activity until you can eat, drink, and move around without dizziness.
Anti-diarrheal medicines such as loperamide may help some adults manage short-term symptoms. However, they are not suitable for everyone.
Do not use them without professional advice when:
A pharmacist or GP can advise whether medication is appropriate.
During recovery, some foods and drinks may aggravate symptoms. Consider limiting:
Once symptoms improve, reintroduce your usual foods gradually.
The duration depends on the cause.
Arrange a GP appointment online if symptoms are not improving, keep returning, or are affecting your ability to eat, drink, work, or sleep.
Diarrhea caused by a virus or bacterium can be contagious. Infection may spread through contaminated hands, food, water, toilets, towels, and frequently touched surfaces.
To reduce transmission:
Alcohol hand gel may not be sufficient against some stomach viruses, so proper handwashing remains essential.
Seek medical advice when diarrhea:
A clinician may recommend a physical assessment, medication review, stool sample, or blood tests. Our private blood testing service can support investigations when clinically appropriate.
Where a specialist opinion is needed, a GP can arrange specialist consultation and referral.
Seek urgent medical help if diarrhea is accompanied by:
Call emergency services when symptoms are severe or life-threatening.
A doctor will usually ask about:
Depending on the findings, investigations may include:
Blood tests can provide useful information about infection, inflammation, anaemia, thyroid function, and nutritional deficiencies. Read our guide to understanding blood test results.
Not every episode is preventable, but good hygiene and food safety can reduce the risk.
Helpful steps include:
Some travellers may benefit from specific vaccinations depending on their destination. For example, cholera vaccination may be recommended in selected circumstances. Learn more about the cholera vaccine and typhoid vaccination.
Diabetes can sometimes affect digestion, particularly when blood glucose levels are poorly controlled or when certain medicines cause gastrointestinal side effects. Recurrent symptoms require a medical review rather than self-diagnosis.
People concerned about their blood sugar can learn more about diabetes testing and the different types, symptoms, and treatment of diabetes.
Some weight-management medicines can cause gastrointestinal side effects, including diarrhea, nausea, vomiting, or abdominal discomfort. Symptoms are often more noticeable when treatment begins or the dose increases.
Contact your prescriber if symptoms are severe, persistent, or causing dehydration. Do not change your dose without medical guidance.
For further information, read our comparison of Wegovy, Mounjaro, and Ozempic.
Diarrhea is usually short-lived, but it should not always be dismissed. Focus on hydration, eat small meals as tolerated, practise careful hygiene, and monitor for warning signs.
Persistent, recurring, bloody, or severe diarrhea requires medical assessment. Identifying the cause early can help prevent dehydration, treat infection when necessary, and uncover digestive conditions that need longer-term care.
For personalised advice, book an online GP consultation, arrange a GP video consultation, or Private Medical Clinic.
The most common cause of acute diarrhea is a viral infection, although food poisoning, medicines, food intolerances, and stress can also trigger it. Persistent diarrhea may be linked to a digestive or medical condition.
There is no single instant cure. The safest first step is to replace lost fluids and electrolytes, rest, and eat small meals as tolerated. Anti-diarrheal medication may help some adults but should not be used when blood, high fever, severe pain, or certain infections are present.
Water and oral rehydration solutions are usually the best options. Clear soup and electrolyte drinks may also help. Take frequent small sips if nausea makes drinking difficult.
Simple foods such as rice, toast, bananas, oats, potatoes, soup, and plain pasta may be easier to tolerate. Resume a varied diet gradually as your appetite returns.
Some people temporarily find dairy harder to digest after a stomach infection. Avoid it only when it clearly worsens symptoms, then reintroduce it gradually after recovery.
Yes. Stress can speed up bowel activity through the gut-brain connection. Recurrent stress-related diarrhea should still be assessed to exclude other causes.
Yes. Antibiotics can disrupt normal gut bacteria and cause mild diarrhea. Severe, persistent, or bloody diarrhea during or after antibiotics requires prompt medical advice.
Yes. Food poisoning commonly causes diarrhea, abdominal cramps, nausea, vomiting, and sometimes fever. Symptoms may begin within hours or several days after eating contaminated food.
Possible signs include thirst, dry mouth, dark urine, reduced urination, dizziness, fatigue, and weakness. Confusion, fainting, or almost no urine may indicate severe dehydration and require urgent care.
Diarrhea that persists for more than a few days without improvement should be discussed with a healthcare professional. Symptoms lasting more than four weeks are considered chronic and need investigation.
Seek medical advice for blood in the stool, black stools, severe abdominal pain, persistent vomiting, high fever, dehydration, unexplained weight loss, or recurring symptoms.
Yes. A GP may review your symptoms and medicines, examine you, and arrange stool tests, blood tests, or specialist investigations when necessary.
Seek advice if symptoms are severe, bloody, persistent, or accompanied by fever or dehydration. Tell the clinician where you travelled, what you ate or drank, and whether you took antibiotics.
A persistent change in bowel habit can be associated with bowel cancer, especially when accompanied by blood in the stool, unexplained weight loss, abdominal pain, or anaemia. These symptoms have many possible causes, but they should be assessed promptly.
It can be. Viral and bacterial diarrhea may spread through contaminated hands, food, water, surfaces, and close contact. Careful handwashing and bathroom hygiene can reduce transmission.
You should generally avoid work, school, nursery, or food preparation while you have infectious diarrhea and for the recommended period after symptoms stop. Follow advice from your employer, school, healthcare provider, or local public-health authority.
Do not give a child anti-diarrheal medicine unless a healthcare professional specifically recommends it. Preventing dehydration is the priority, and children with warning signs should receive prompt medical advice.
Some probiotics may shorten certain types of infectious or antibiotic-associated diarrhea, but their effectiveness varies by strain and situation. Ask a healthcare professional whether a probiotic is appropriate for you.
No. Diarrhea is a symptom, not a healthy detoxification process. It can cause dehydration and electrolyte loss, particularly when severe or prolonged.
Yes. An online GP service may be suitable for discussing symptoms, medications, travel history, and next steps. An in-person examination may still be advised when symptoms are severe or tests are needed.
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