During a case of diarrhoea, you may feel bloated. And your bowel movements (faeces or stools) become loose and very soft or watery. Most of the time, it isn’t serious, but there are signs you should look out for.
This blog post covers the causes of diarrhoea. It then explains when you should see a doctor for advice or diagnostic examinations.
In some cases, patients will need an endoscopy-based procedure called a colonoscopy (explained later). This is to identify or rule out conditions like inflammatory bowel disease or bowel cancer.
Possible causes of diarrhoea
Diarrhoea is a very common illness that can affect babies, children and adults. It is most often caused by a ‘stomach bug’ (or, as doctors call it, gastroenteritis). This is an infection of the bowel, which can be from:
- A virus such as norovirus (which also causes vomiting)
- Bacteria such as Escherichia coli (E. coli) from food poisoning/contamination
- A parasite from contaminated water (usually when travelling abroad)
This kind of diarrhoea should be over within a couple of days or so. You can treat this yourself by resting at home, which also reduces the spread of infection. Also, drink plenty of water to prevent dehydration (avoid fruit juices).
Rehydration sachets and over-the-counter medicines from a pharmacy can also help. Please note: diarrhoea medicines are not suitable for young children (under age 12).
Sometimes these treatments don’t stop the diarrhoea, or it comes back frequently. In these situations there may be a different reason for your change in bowel habits. There are many possible causes of diarrhoea, including:
- Allergies or food intolerance
- Bowel polyps
- Cancers, such as bowel cancer
- Coeliac disease
- Crohn’s disease
- Diabetes
- Diverticular disease and diverticulitis
- Excessive alcohol consumption
- Inflammatory bowel disease (IBD)
- Irritable bowel syndrome (IBS)
- Laxative overuse
- Malabsorption
- Medication side effects
- Overactive thyroid (hyperthyroidism)
- Low pancreatic enzymes
- Microscopic colitis (inflammation that is only visible on tissue samples)
- Anxiety and/or stress
Diarrhoea can also happen following surgery on your digestive system or radiation therapy.
You would normally experience other symptoms as well as diarrhoea if you have a serious condition. Next we’ll explain the main things to be aware of.
When to see a doctor
Call a doctor when your diarrhoea is persistent (more than a few days) or if symptoms include any of the following:
- Bleeding from your bottom
- Blood in your poo (blood will make your stools very dark)
- Mucus in your bowel movements (mucus can make your stools appear oily or slimy)
- High fever lasting more than 24 hours
- Severe abdominal pain and/or headache
- Unexpected weight loss
- Vomiting so much that you can’t drink enough fluids.
Why might you need a colonoscopy?
Many people will need to have a colonoscopy at some point in their lifetimes. It is one of the options available to specialists when diagnosing digestive conditions. But before then, we would ask you a series of questions about your symptoms.
You will normally also need to provide a stool sample, which a laboratory will analyse. For example, this can reveal if the diarrhoea is due to infection or immune system weakness.
We are likely to do blood tests, especially when diagnosing inflammatory bowel disease.
GPs and specialists may also carry out a digital rectal examination. A doctor puts on a surgical glove and inserts their finger into your bottom. This is to inspect for abnormalities affecting your rectum and bowel.
In general, a colonoscopy is a safe and effective way to inspect the bowel more thoroughly. This is especially useful if other tests were inconclusive.
Digestive specialists may use a colonoscopy to check the colon for signs of:
- Bleeding
- Blockages
- Bowel polyps (small growths inside the lining of the large intestine or rectum)
- Diverticular disease and diverticulitis
- Inflammation (redness or swelling)
- Tumours
- Ulcers (ulcerative colitis)
We can also take tissue samples (a biopsy) during a colonoscopy, which we send to a lab for testing.
A colonoscopy most often takes less than an hour. It’s an important test if you experience persistent bowel problems such as chronic diarrhoea. It uses a narrow tube containing a small light and camera at the end. When doctors only need to examine your lower bowel it’s called a sigmoidoscopy, but the process is similar.
Colonoscopies enable your doctor to see the entire length of your colon for checking and removing polyps and other growths. Polyps, which develop in many people as they get older, are often harmless and cause no symptoms. But certain kinds (known as adenomas) may become cancerous over a long time.
Watch our animated video to learn more about colonoscopy, a type of endoscopy:
[answerpacktv video=”endoscopy-all-you-need-to-know” header-only=”yes” single-view-mode=”yes” view-playlist-label=”View more videos” header-link=”/videos/answerpack/endoscopy” landing-page-header-text=” ” landing-page-header-title=”Endoscopy: All you need to know”]
Book an appointment
Although you may be anxious if you have not had a colonoscopy before, we will make it as comfortable as possible. When used for diagnosis or treatment, it is a much less invasive procedure than open surgery.
To find out more about having a private colonoscopy in London, please get in contact to book an in-person or remote consultation.
