Many people have problems with diarrhoea, not everyone knows why.

IMODIUM® has helped bring relief to millions of diarrhoea sufferers for almost 40 years. During this time we've collected a lot of knowledge about diarrhoea, its causes and symptoms, and especially how to treat it. Here are some of the questions we're asked most often, along with our answers.

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If you have a question about our products, please take a look at our Frequently Asked Questions, to see if these help prior to contacting us:

1. What is diarrhoea?

When your digestive system is in its normal rhythm, food and fluid pass regularly from the stomach into the small intestine, food is then broken down and nutrients absorbed along with most of the fluid. The remaining waste and some water then pass into the colon, (large intestine) where more water is absorbed and finally the waste is passed in the form of stools.
When the cells in your small intestine or colon become irritated the relaxed and regular movement of your intestines can become overactive. Essential salts and fluids end up being passed through the colon too quickly with less fluid absorbed by the body.
The result of this is loose or watery stools, commonly known as diarrhoea.

2. What causes diarrhoea?

Everyone is familiar with the occasional bout of short-term diarrhoea.

Here are some of the main causes to watch out for:

Typically episodes of diarrhoea clear up within a few days, but can last longer. Most people only experience diarrhoea from time to time, but for some people it can be more frequent. Research In fact 14% of the population are frequent sufferers of diarrhoea and can suffer once a month or more (Ipos Marketing Need State Study, July 2008). Are you one of them? Longer lasting or persistently recurrent diarrhoea can indicate an underlying medical condition, so you may need to consult your doctor.

3. Should I treat diarrhoea?

If you are feeling weak and lacking in energy when suffering from diarrhoea why leave it untreated when you can relieve diarrhoea and help reduce the loss of fluids and salts in the process. Here’s what healthcare professionals say:


  • Experts in this field recommend that acute (short-term) diarrhoea in otherwise healthy adults can be self-medicated without delay - and in fact there is no advantage in letting diarrhoea run its course.
  • Gastroenterologists also recommend Loperamide as the ‘treatment of choice’ for the relief of diarrhoea symptoms.
  • Make sure you drink plenty of fluids to ensure you remain well hydrated. Consider oral rehydration sachets if you risk becoming dehydrated.
  • However if you have a high temperature, blood in your stools, or your diarrhoea has not improved over 24 hours you should talk to you doctor.
  • Longer lasting or more persistent diarrhoea can indicate an underlying medical condition, so you may need to consult your doctor.

NHS Choices recommends you should consult your GP if you have:

  • recently been treated in hospital
  • recently been treated with antibiotics
  • diarrhoea that has blood in it
  • diarrhoea and persistent vomiting
  • unexplained weight loss
  • bleeding from your rectum (back passage)
  • passed large volumes of very watery diarrhoea (you may be at risk of dehydration)
  • symptoms at night that are disturbing your sleep
  • diarrhoea that lasts longer than a week

If your symptoms are suitable for self-medication, IMODIUM® has designed a range of products to suit your needs.


Product Benefits Available over the counter in pharmacies
IMODIUM® LiquiRelief
  • The liquid filled capsules provide gentle, soothing relief from diarrhoea
  • Fast and effective-can stop diarrhoea in 1 hour
  • The small capsules are discreet and easy to swallow
  • Flavour free
IMODIUM® Instants
  • Fast and convenient relief
  • Can stop diarrhoea in less than 1 hour
  • Melt on the tongue in seconds
  • No water needed
  • Most effective multi symptom relief available
  • Helps to relieve diarrhoea, painful stomach cramps, wind and bloating
  • Easy to swallow tablets
4. Do I need a prescription for IMODIUM®?

No, you don’t need a prescription to buy IMODIUM®. As a trusted diarrhoea treatment, IMODIUM® is widely available in pharmacies.

5. Should I let diarrhoea run its natural course?

Many people believe that it’s best to let diarrhoea run its course in order to ‘flush’ bacteria and toxins out of the system. In fact, diarrhoea is not always caused by bacterial or viral infection; there are a whole host of other causes. Many things can ‘tip the balance’ of our sensitive digestive systems. In fact, just a small reduction in the efficiency of fluid absorption of our bowels can lead to a bout of diarrhoea - so it’s easy to understand how diarrhoea can happen. Diarrhoea is actually a symptom of disruption to the finely tuned system, rather than a defence mechanism: it is your immune system that fights infection, so there is no need to leave diarrhoea to run its course. So why endure it when you can relieve it? You don’t have to suffer in silence; you can treat your diarrhoea and get back in control. IMODIUM® can stop diarrhoea within one hour.

6. Can I take IMODIUM® when pregnant or whilst breastfeeding?

As with many medicines, IMODIUM® is not recommended during pregnancy or while breastfeeding. If you’re pregnant or caring for a newborn, diarrhoea can often be the last thing you want to deal with. However, you shouldn’t worry as in most cases drinking fluids, eating healthily and resting should help you recover. If you are concerned it’s best to consult your GP for advice.

7. Can my child use IMODIUM®?

IMODIUM® is not recommended for children under 12 years of age. Children can become dehydrated more quickly; so oral hydration treatments are recommended if your child is under 12. If their diarrhoea lasts longer than 48 hours, or you are otherwise concerned about their health you should consult your doctor.

8. Will an oral rehydration solution treat my diarrhoea?

Oral rehydration solutions replace lost fluids and electrolytes, and help prevent dehydration but do not relieve the symptoms of diarrhoea. However, to help stop diarrhoea you can also use IMODIUM® together with an oral rehydration solution.

9. Does IMODIUM® always cause constipation?

IMODIUM® contains an active ingredient called Loperamide that works in harmony with your body to help restore its natural rhythm, gently slowing digestion back down to a normal pace. Contrary to popular belief, diarrhoea treatments like IMODIUM® don’t prevent stools from passing. When used correctly constipation is rarely a problem. After a bout of diarrhoea you naturally feel empty and it can take time for your bowel to return to its normal pattern.

10. Why do I suffer from diarrhoea on holiday?

Travellers’ diarrhoea has many causes, from contaminated food to foreign bugs your body isn’t immune to. Travellers’ diarrhoea is very common and at its worse it can spoil your holiday, so it’s a good idea to pack IMODIUM® before travelling. IMODIUM® Instants are particularly helpful if you’re on the go, as they melt in your mouth and work within one hour.

11. When I drink a lot or eat a lot I often get diarrhoea. Why is that?

Overeating and drinking can upset our digestive system and lead to diarrhoea. So, always try to eat sensibly and avoid excess! However, if diarrhoea does occur, IMODIUM® can quickly relieve the symptoms within one hour and help you get your body back in harmony again.

Here are a few everyday habits that can upset your digestive system. Try to avoid:

  • Eating too quickly – it takes 20 minutes for your stomach to tell your brain that it’s full, so eating more slowly means you may eat less and therefore have less to digest
  • Gulping down food – when you gulp, you swallow air, which can lead to trapped wind and poor digestion
  • Eating too many fatty and spicy foods or drinking too much alcohol
  • Eating big, heavy meals – these take longer to digest and make your system work harder
  • Eating late at night – your digestive system is at its slowest at the end of the day. Try to eat your last meal of the day at least 3 hours before bedtime
12. I get nervous when I make speeches and get an upset stomach. Why is this?

Diarrhoea caused by having to perform in public is such a well-recognised problem; it even has its own name – Performance Anxiety Diarrhoea (PAD). If you know you are likely to have a problem, having a pack of IMODIUM® Instants to hand and taking it at the first sign of diarrhoea, can give you the confidence you need to perform at your best.To find out more, visit our Stress and diarrhoea section.

13. I get cramps, bloating and wind with diarrhoea. What can I take?

For some people, diarrhoea is accompanied by the uncomfortable symptoms of stomach cramps, wind and bloating, which are all caused by excess gas in the gut. IMODIUM® Plus is specially designed to treat this uncomfortable combination of symptoms, so you can carry on with what you need to do.

14. Why do I get diarrhoea when I have my period?

Approximately a third of women, who do not normally suffer from bowel complaints, experience gastrointestinal symptoms around the time of menstruation. It can cause discomfort and make you feel self-conscious, but you don’t have to let it ruin your day. IMODIUM® can quickly help relieve diarrhoea during your period.

15. I’m embarrassed to ask for a diarrhoea treatment. What should I do?

Diarrhoea has emotional as well as physical effects and diarrhoea treatment can be embarrassing to ask for. But it’s good to remember that diarrhoea is one of the most common complaints your pharmacist deals with. In fact 14% of the population are frequent sufferers of diarrhoea. (from - Ipos Marketing Need State Study, July 2008). Your pharmacist is trained to offer you the best treatment possible, so you can always ask to speak to them in private to get their advice.

16. I don’t like swallowing tablets. What treatment should I use?

IMODIUM® Instants are specially made to dissolve on your tongue, so you can get rapid relief from diarrhoea within 1 hour without having to swallow or use water. Perfect for when you’re on the go.

17. I have bought an IMODIUM® product but I have lost the leaflet. Can I obtain a copy?

Patient Information Leaflets (PILs) can be found on the electronic Medicines Compendium at:

18. I’m unsure what’s causing my frequent diarrhoea. What should I do?

Most people experience diarrhoea from time to time but for some it’s more frequent. Frequent or more persistent diarrhoea can be a sign of an underlying medical condition and you may need to visit your GP. Everyone is different and people can find it difficult to identify the cause of their frequent diarrhoea. For some it could be eating habits or food intolerances, for others it could be due to menstruation or Irritable Bowel Syndrome, and some people react to stress and anxiety brought on by a busy modern lifestyle. Its good to understand your body to help manage symptoms accordingly. We offer tips and advice to help improve your digestive health and well-being.

19. What is norovirus?

Norovirus is the most common cause of viral gastrointestinal illness, which often leads to diarrhoea. Norovirus is very contagious and can spread quickly if you don’t wash your hands regularly. If you have diarrhoea as a result of norovirus, you can treat the symptoms with IMODIUM®.