Diarrhoea

What is diarrhoea?

Diarrhoea is a common problem where your stools (poo) become loose, and/or watery. You may also need to open your bowels more often.

Diarrhoea is a symptom, rather than a condition in itself and can have several possible causes. It may start quickly and last for a short time or be long-lasting- which can be a sign of something more serious.

Types of diarrhoea

There are three main types of diarrhoea, depending on how long your symptoms last.

• Acute diarrhoea - this is the most common type of diarrhoea that lasts for one to two days. Common causes include food poisoning or a viral infection
• Persistent diarrhoea - lasts for between two and four weeks and is commonly due to an infection or a side effect of medication
• Chronic diarrhoea - lasts for more than four weeks and may be caused by a food intolerance/allergy or an underlying health condition such as irritable bowel syndrome (IBS), Crohn's disease, coeliac disease or ulcerative colitis

What causes diarrhoea?

Diarrhoea can have several causes including:

• a viral, bacterial or parasitic infection such as rotavirus, E coli, or campylobacter
• eating contaminated food
• food intolerance such as intolerance to lactose or gluten
• food allergy
• anxiety
• laxative abuse
• a side effect of some medications like antibiotics
• inflammatory bowel diseases (IBD) like Crohn's, or ulcerative colitis
• irritable bowel syndrome (IBS)
• difficulty absorbing certain nutrients (malabsorption)
• surgery on your stomach, bowels or gallbladder
• radiation treatment to your pelvic area
• some cancers

Rotavirus

Rotavirus is the most common cause of gastroenteritis in babies and young children and can lead to serious dehydration and hospitalisation. The symptoms of rotavirus usually last from three to eight days and include severe watery diarrhoea, fever, abdominal pain and vomiting. Adults can also get rotavirus, but symptoms are usually less severe.

In the UK, babies are given two doses of the rotavirus vaccine at eight and twelve weeks of age as part of the NHS vaccination schedule.

Diarrhoea after eating (postprandial diarrhoea)

Postprandial diarrhoea (PD) is diarrhoea that occurs soon after eating. It is often accompanied by abdominal pain and discomfort and can be acute, persistent or chronic. PD can have several causes including infection, food intolerances and long-term conditions like IBS.

PD can also be the result of an overactive gastrocolic reflex, the natural reaction that occurs in your body when you consume food. When you eat, your body releases hormones that tell your colon to contract to move food through your intestine and out of your body. In some people, the gastrocolic reflex is stronger and occurs more frequently causing diarrhoea after eating. This can be caused or made worse by certain foods or medical conditions including:

• inflammatory bowel disease (IBD)
• celiac disease
• food allergies and intolerances
• anxiety
• gastritis
• irritable bowel syndrome (IBS)
• greasy food

An intense gastrocolic reflex that causes diarrhoea within 30 minutes of eating may indicate early dumping syndrome, a condition where food moves too quickly from your stomach to your small intestine, triggering the release of excessive hormones and causing the intestines to swell. Symptoms include diarrhoea, abdominal pain, bloating, nausea, vomiting, sweating, palpitations, dizziness and fatigue.

What are the symptoms of diarrhoea?

The main symptom of diarrhoea is thin, loose, watery, unformed stools. You may also have other symptoms including:

• abdominal (tummy) pain/cramps
• bloating
• needing to use the bathroom urgently, and/or frequently
• nausea
• vomiting
• fever (high temperature)
• bloody stools
• mucus in your stool
• leaking stool and not being able to control your bowels (faecal incontinence)

Diarrhoea complications

The main complication of diarrhoea is dehydration. This is especially common in babies and young children and can come on quickly. Severe dehydration can be very serious and may lead to fainting, shock, organ damage, and coma.

If you have diarrhoea, avoid dehydration by drinking plenty of fluids such as water or squash. It may be easier to take small, frequent sips, especially if you feel sick.

Avoid fizzy drinks or fruit juice as they can make your symptoms worse.

Symptoms of dehydration in adults include:

• thirst
• dry mouth and nostrils (mucous membranes)
• headaches
• fatigue
• passing small amounts of dark-coloured urine
• dry skin
• feeling faint or lightheaded
• rapid heart rate
• confusion (more common in older people)

Symptoms of dehydration in babies and children include:

• sunken fontanelle (soft spot) on your baby's head
• peeing less or fewer wet nappies
• dry or sticky mouth
• sunken eyes
• restlessness, fussiness or irritability
• few or no tears when crying
• drowsiness
• dizziness

When to see a doctor

Make an appointment with your consultant if:

• you have diarrhoea for more than two days without any improvement
• you have a high fever (above 39C)
• you have symptoms of dehydration
• you have severe abdominal or rectal (back passage) pain
• you notice blood in your stools, or you have black stools

Make an appointment for your baby or child if:

• they have diarrhoea for more than 24 hours
• they show signs of dehydration
• they have a temperature above 39C
• they stop bottle or breastfeeding
• they have bloody or black stools

How is diarrhoea diagnosed?

Your consultant will diagnose diarrhoea by asking about your symptoms and performing a physical examination.

They may also ask you about:

• your general health
• your medical history
• any medications you are taking
• any recent travel overseas
• your family history
• any recent exposure to infection or food poisoning you are aware of

If your diarrhoea may be more serious, your consultant may order some tests to try to find out the cause of your diarrhoea. These may include:

• blood tests to rule out certain medical conditions that can cause diarrhoea, and to check your electrolytes and kidney function
• a stool test to check for blood, bacterial infections and parasites
• a hydrogen breath test to check for lactose or fructose intolerance and small intestine bacterial overgrowth (SIBO)
• tests for food intolerance and food allergy
• an endoscopy - a procedure where a thin flexible tube with a camera is used to examine your upper digestive tract to check for abnormalities and take tissue samples if necessary
• flexible sigmoidoscopy or colonoscopy - a thin, flexible tube with a camera is inserted into your rectum to allow your consultant to examine your colon for abnormalities or disease

Treatment for diarrhoea

Diarrhoea usually clears up on its own without treatment, but in some cases, your GP may prescribe medication such as antibiotics or refer you for further tests to determine the cause of your diarrhoea.

Home treatment for diarrhoea

• rest
• drink plenty of fluids (water is best)
• eat when you feel able - small amounts of bland food such as dry toast, crackers, apple sauce, bananas, plain rice or boiled potatoes
• avoid spicy or fatty foods as they can make your symptoms worse.

Over-the-counter medicines for diarrhoea

Some over-the-counter medicines can help relieve symptoms of diarrhoea, replace lost electrolytes or support your gut as it heals. Over-the-counter medicines should only be used to treat short episodes of acute diarrhoea. If your diarrhoea has not improved after two days, make an appointment to see your consultant.

Some over-the-counter medications that can help with symptoms of diarrhoea include:

• paracetamol - can help with symptoms such as headache and abdominal pain
• probiotics - are a type of good bacteria that help keep your intestines healthy. They may help with some types of diarrhoea, such as antibiotic-induced diarrhoea, infectious diarrhoea and traveller's diarrhoea
• oral rehydration salts - do not treat diarrhoea, but replace lost electrolytes such as magnesium and potassium due to dehydration

How to stop diarrhoea

It's normally better to let a bout of acute diarrhoea run its course but if you need immediate short-term relief, antidiarrheal medications such as loperamide (Imodium) can relieve symptoms of diarrhoea quickly.

Loperamide works by slowing down the movement of food as it passes through your gut. This allows your intestines to absorb more water making your stools firmer and less frequent, helping to restore normal bowel function and preventing dehydration.

Loperamide should not be given to children under 12 unless advised by a doctor.

Can diarrhoea be prevented?

While some types of diarrhoea can't be prevented, there are some precautions you can take to reduce your risk of getting infective diarrhoea and spreading it to others.

To minimise the risk of spreading diarrhoea to other people:

• if your diarrhoea is accompanied by a fever and/ or feeling generally unwell, avoid contact with others until you feel better
• wash your hands frequently with soap and water (use hand sanitiser if soap and water is unavailable)
• disinfect toilets, taps, surfaces and door handles every day
• do not prepare food for other people, if possible
• do not share towels, flannels, cutlery or utensils
• do not use a swimming pool until at least 48 hours after your symptoms stop

To minimise the risk of traveller's diarrhoea (especially in developing countries)

• don't drink tap water (including ice made from tap water) or use it to brush your teeth
• avoid drinking unpasteurised milk or milk products
• stick to fruits and vegetables that can be cooked or peeled
• avoid raw or undercooked meat or seafood
• ensure food is cooked thoroughly and served hot
• avoid eating food from street vendors or food trucks

Summary

Diarrhoea is a common condition that normally goes away without treatment after a few days. In some cases, diarrhoea can be a sign of something more serious and may need treatment. Severe or prolonged diarrhoea can lead to dehydration, which can be dangerous, especially in babies and young children.

If you are worried about diarrhoea symptoms in yourself, or your child, make an appointment to see a consultant.