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Common causes of diarrhoea in the Western world include the following:
This can typically be caused by viruses or bacteria. Infections can be transmitted through contaminated food or from person to person, and outbreaks in confined environments are quite common (most of us have heard of rotavirus outbreaks in cruise ships or hospitals). The majority of these are usually self-limiting after a few days, and they do not require specific treatment. Certain intestinal infections can persist for longer periods and cause chronic diarrhoea, especially in the elderly and people with weakened immune systems (immunocompromised).
Our lab at OneWelbeck use the most up-to-date techniques in identifying pathological micro-organisms in stool specimens.
This is a common cause of diarrhoea that is often overlooked. There is a large number of drugs that can cause chronic diarrhoea, including several antibiotics, antacids, medications for high blood pressure, anti-inflammatories, medications for diabetes and others. A careful medication history is crucial in assessing patients with persistent diarrhoea as this can be easily addressed by stopping the offending tablets.
3) Inflammatory bowel disease (IBD)
IBD, which comprises Crohn’s disease, ulcerative colitis and microscopic colitis are inflammatory conditions of the gastrointestinal tract which are encountered with increasing frequency. Diarrhoea, which often contains blood, is frequently the cardinal symptom in these conditions. IBD is diagnosed with a colonoscopy, an examination where the bowel is inspected with the use of a flexible camera, during which small samples from the lining can be obtained and examined under the microscope. IBD should always be considered and ruled out in young people with persistent diarrhoea, especially if this is associated with abdominal pain and weight loss.
More recently a subtype of IBD called Microscopic Colitis has been described, where the bowel looks completely normal on colonoscopy, but samples of tissue inspected under the microscope reveal microscopic evidence of inflammation. Therefore, your colonoscopist will discuss with you the option of obtaining 4-6 biopsies during the procedure, even if the lining of the bowel looks completely normal to the naked eye, in order for Microscopic Colitis not to be missed.
4) Irritable bowel syndrome (IBS)
IBS is a very common condition associated with changes in bowel habit, bloating and abdominal pain. Diarrhoea is a common manifestation. Whilst we know that it is generally a benign condition not driven by an underlying inflammation or other serious pathology, the symptoms can be particularly persistent and distressing.
Unfortunately, the exact cause of IBS has not been uncovered yet, but research is currently focused on identifying specific gut microbial profiles and dietary factors that can either exacerbate or protect against the syndrome. We also know that stress can contribute significantly to IBS symptoms.
Potential treatment strategies include dietary interventions, as well as pharmacological options for more persistent cases. There is also evidence that hypnotherapy, behavioural therapy and complimentary approaches can also be of benefit in some patients.
5) Bile acid diarrhoea
This is another common cause of chronic diarrhoea that is frequently overlooked. Bile acids are produced by the liver and secreted in the upper gut in response to a meal to help with its digestion. Normally, these are reabsorbed in the lower small bowel in order to enter the same cycle again. If this cycle is interrupted, bile acids enter the large bowel which can cause chronic diarrhoea by coming into contact with its lining. Once this is diagnosed, it is usually relatively straightforward to manage with the use of medications that prevent that contact between bile acids and the colonic wall.
6) Food intolerances or coeliac disease
Food intolerances are also quite common. A subset of people readily develop symptoms including cramping, bloating and diarrhoea in response to dairy products. This can be attributed to lactose intolerance.
Wheat is another common trigger, a severe form of which is coeliac disease. Coeliac disease is seen in up to 1% of the population and is caused by inflammation driven by gluten, a protein commonly found in wheat, rye and barley. A careful dietary history and screening blood tests for coeliac disease form part of the routine assessment of patients with diarrhoea.
7) Pancreatic insufficiency
Issues with the function of the pancreas, a gland located behind the stomach which has a crucial role in digestion, can cause chronic diarrhoea. This is due to inadequate production or secretion of digestive enzymes, in response to fatty food in particular. The commonest, but by no means sole cause of pancreatic insufficiency, is chronic alcohol abuse. In addition to being harmful to the pancreas, alcohol also has a direct deleterious effect on intestinal cells, which in turn can cause chronic diarrhoea.
Get in touch today
If you would like to speak to one of our specialists about chronic diarrhoea, or any other concerns you might have regarding your digestive health, please do not hesitate to get in touch with us today.
Written by Dr Evangelos Russo, Consultant Gastroenterologist at OneWelbeck Digestive Health, specialising in therapeutic colonoscopy, inflammatory bowel disease and microscopic colitis.