Diarrhoea

What causes diarrhoea?

Diarrhoea has many causes. One of the most common is food poisoning, when bacteria from contaminated food is ingested. Another common cause is viral infections such as flu, norovirus or rotavirus (the latter especially in young children). Tiny parasitic organisms found in contaminated water can also lead to diarrhoea.

Other factors that can cause it are allergies to certain medicines such as antibiotics, cancer drugs and antacids (used to help with indigestion) that contain magnesium. Similarly, allergies or sensitivities to certain foods, for example those that are lactose intolerant, can trigger diarrhoea. You may also get diarrhoea if you have irritable bowel syndrome (IBS) or a disease that affects the stomach, small intestine or colon such as Crohn’s disease.

Conditions which affect the large intestine (or bowel) such as diverticulitis can cause diarrhoea too.

Sometimes no direct cause can be found. But if your diarrhoea goes away relatively quickly, finding the root cause is not necessarily a key concern other than to avoid future episodes from reoccurring.

Always remember to stay off work, or in the case of children, keep them off school until there have been no incidents of diarrhoea for at least 2 days afterwards. This reduces any potential spread of infection to others.

What are the symptoms of diarrhoea?

The main symptom is passing runny or liquid stools, often on a frequent basis over a day or two and in more severe cases up to a week. Other symptoms may include stomach cramps, nausea and vomiting. In extreme cases, a total loss of bowel control (incontinence) may be experienced.

Can diarrhoea lead to other problems?

Although diarrhoea is not usually harmful, it can become dangerous if prolonged. Or it may be an indication of a more serious underlying problem.

As the body can lose liquid rapidly as a result of diarrhoea, one of the most dangerous problems associated with this condition is dehydration (symptoms include dark, pungent urine, or urinating less than usual). So it’s important to ensure that you keep yourself regularly hydrated when suffering from bouts of diarrhoea.

You should always contact a clinician if there’s any blood in your stool, if you have extreme abdominal or rectum pain, or if you experience significant weight loss or continuous vomiting.