What is Microscopic Colitis?
Microscopic colitis is a chronic condition which causes inflammation of the large bowel or colon, and actually encompasses two conditions; Collagenous and Lymphocytic colitis. These conditions are referred to as “microscopic”, because unlike other inflammatory bowel diseases such as Crohn’s disease and Ulcerative colitis , there is no sign of inflammation of the lining of the intestine when viewed during a Colonoscopy procedure. Microscopic colitis can only be diagnosed by biopsies of the colon which demonstrate inflammation on the microscope.
What is the cause of Microscopic Colitis?
There are a number of theories regarding the cause of microscopic colitis, although the precise cause is unknown. It is thought that a number of medications may be associated with microscopic colitis and cessation of these drugs may lead to an improvement in symptoms. Although the symptoms of collagenous colitis and lymphocytic colitis are similar, it is also unclear whether the two conditions are related.
What are the symptoms Microscopic Colitis?
Microscopic colitis typically causes chronic watery diarrhoea. These symptoms may either occur on an intermittent (more common) or continuous basis. Other associated symptoms may include abdominal discomfort, weight loss and lethargy. It does not cause bloody diarrhoea or rectal bleeding.
Who gets Microscopic Colitis?
Microscopic colitis is a relatively uncommon condition, and is generally diagnosed in middle aged and elderly individuals. Collagenous colitis is more common in females (female to male ratio 15:1). Lymphocytic colitis has no gender preponderance.
How is Microscopic Colitis diagnosed?
Microscopic colitis diagnosed on the basis of a normal colonoscopy , with biopsies of the colon demonstrating characteristic “collagen” changes or an increased number of “lymphocytes” in the lining of the intestine. Collagen is a protein which is part of scar tissue, whereas lymphocytes are a specific type of white blood cell in the immune system. The inflammatory changes seen in microscopic colitis may only be patchy and not affect the entire colon, and so multiple biopsies from different parts of the colon are recommended.
How is Microscopic Colitis treated?
The treatment for microscopic colitis depends on the severity of the symptoms, and can include anti-diarrhoeal (e.g. loperamide), anti-inflammatories (e.g. sulfasalazine or mesalazine) or steroids (e.g. budesonide). Some people are able to cease their medication without a recurrence in their symptoms, although relapse requiring repeated medical therapy may also occur.
Can Microscopic Colitis cause cancer?
There are no reported evidence of a link between microscopic colitis and cancer.