What is microscopic colitis?
Microscopic colitis, sometimes called MC for short, is a type of inflammatory bowel disease (IBD). It causes your large intestine, also known as colon, to become inflamed. This is why it’s called ‘colitis’.
Microscopic colitis is most easily identified by the symptom of watery diarrhoea, accompanied by the feeling of needing the toilet urgently and tummy pain. It’s known as microscopic colitis because the inflammation is usually only visible under a microscope.
What are the types of microscopic colitis?
There are 2 types of microscopic colitis: collagenous colitis and lymphocytic colitis. Both types have the same symptoms but look different under a microscope.
Collagenous colitis (CC)
With collagenous colitis, the layer of collagen in the wall of the colon becomes thicker than normal. There may also be more white blood cells called lymphocytes than normal.
Lymphocytic colitis (LC)
In lymphocytic colitis, white blood cells called lymphocytes build up in the wall of the colon.
What are the symptoms of microscopic colitis?
The symptoms of microscopic colitis are unpleasant as they often come on with much urgency. These symptoms include:
Watery diarrhoea, especially at night
Frequent need to poo or incontinence
These symptoms may affect your lifestyle as you feel you have to find where the nearest toilet is on every occasion. This can be immensely frustrating.
Some people with the condition have said that there is fatigue caused by microscopic colitis symptoms.
How common is microscopic colitis?
Microscopic colitis is thought to be underdiagnosed as it is similar to other inflammatory bowel diseases. In particular, the symptoms of MC can have a lot of overlap with the symptoms of IBS.
This means it is very difficult to know how common the condition really is, but it may be more common than once believed. Researchers have estimated that microscopic colitis is just as common as Crohn’s disease and ulcerative colitis at around 10 new cases per 100,000 people every year.
How long does microscopic colitis last?
Microscopic colitis is typically a long-term or chronic condition, but in most cases you will notice the symptoms will come and go. It can be well managed with medications.
What causes microscopic colitis?
The causes of microscopic colitis haven’t been determined by scientists yet but some possible causes may be:
Bacteria and viruses
Over the counter painkillers
Autoimmune problems caused by your immune system attacking itself
Microscopic colitis in children
Microscopic colitis in children is far more rare than in adults. It has the same characteristics as the adult condition.
Who is at risk of microscopic colitis?
Microscopic colitis is more common in some people than others. Those at increased risk are:
Those who smoke
Those who take certain medications
How is microscopic colitis diagnosed?
To diagnose microscopic colitis, you will first be asked some questions about your symptoms. The main questions will be about whether you experience diarrhoea and how often.
You may have some tests done, these may include:
Colonoscopy – this procedure consists of inserting a long, thin tube, with a camera at the end into the bowel. In microscopic colitis, the colon usually looks normal in a colonoscopy.
Biopsy – this is when a small section of your bowel is taken out during a colonoscopy and put under the microscope. This is the stage at which a diagnosis of microscopic colitis can be confirmed.
Blood tests – these can be used to rule out other conditions
Stool sample – this looks in close detail at your poo
There are multiple conditions with the same symptoms as microscopic colitis, this means your doctor will be looking to rule out other diseases to give you a diagnosis.
How to treat microscopic colitis
There are multiple ways to treat microscopic colitis. The treatment chosen for you will be based on your symptoms.
Lifestyle advice may be given to you to help manage your symptoms. This is focused mainly on your diet, and helpful guidance might include:
Eat a lower fibre diet
Try avoiding dairy, gluten or both
Reduce sugar and caffeine in your diet
Medical treatments for microscopic colitis may involve:
Anti-diarrhoea medicines such as loperamide
Immune suppressing medication such as mercaptopurine or azathioprine
In rare instances, if your symptoms are more severe, surgery may be an option to take out part of the colon. This is very uncommon.
When should I speak to a doctor?
If you have watery diarrhoea and are frequently going to the toilet, you should seek advice from a doctor.
How can Livi help?
A Livi doctor can ask you questions about your symptoms and recommend a treatment or refer you to a specialist if needed.
- Reviewed by:
- Dr Bryony Henderson, Lead GP at Livi