Ulcerative Colitis (UC) is a type of Inflammatory Bowel Disease characterized by inflammation involving varying segments of large intestine. Ulcerative Colitis should be suspected and evaluated for in a patient presenting with loose stools mixed with blood for more than 4 weeks. Disease usually presents in the second or third decade of life.
What are the risk factors for UC?
What exactly causes UC is unknown. But as discussed in the Chapter 2, an interplay of multiple factors is responsible for development of UC.
History of UC in a first-degree family member confers a 10-20% risk of developing UC.
Microbial dysbiosis and altered inflammatory cascade in the body are other factors which are proposed risk factors. Over the past few decades, both UC and Crohn’s disease are rapidly increasing in incidence. This is possibly due to increased consumption of packaged and refined foods which usually contain preservatives and food additives.
UC can occur at any age though presentation at extremes of age (Less than 5 years and more than 75 years) is uncommon. Most common presentation is around 20-30 years of age. It is seen equally in both sexes.
Most common symptoms are rectal bleeding, diarrhoea and abdominal pain. Around 30% of patients affected with UC, especially those with rectal involvement may also present with constipation. Patients usually pass blood and mucous mixed stools which are of small quantity. Increased stool frequency including nocturnal episodes and fecal incontinence are other prominent features. Abdominal pain is usually colicky and localised to lower abdomen. Patients usually feel the pain before and during passage of stools and have relative pain free periods during the intervening period.
UC maybe associated with several extra intestinal features which are discussed in Chapter 5.
How is UC diagnosed?
Diagnosis of UC requires a test called Colonoscopy. It involves insertion of an advanced video based flexible tube through the anus into the large intestine to visualise the inner aspect of the large intestine and a small part of the terminal small intestine (ileum). The procedure usually requires bowel preparation with a laxative prior to the procedure. This is done to clear the large intestine of its fecal contents. Colonoscopy procedure requires 5-10 minutes and is usually done on day-care basis unless the patient is very sick. Mild sedation or anaesthesia maybe used for the procedure based on the doctor’s and patient’s preference and underlying condition.
Sometimes, the doctor might even advise you to get a Sigmoidoscopy done which is shorter version of Colonoscopy and requires minimal time (1-2 mins) as the scope is inserted only upto the sigmoid colon; i.e last one feet of the large intestine. No sedation is required for this procedure and there is hardly any discomfort. Rectum is almost always involved in UC, hence even a simple sigmoidoscopy is useful in most cases to start the treatment and assess the severity of disease at diagnosis or follow up.
What is seen on Colonoscopy?
A normal healthy colonic mucosa (innermost lining of the intestine) is glistening in appearance with a lacy pattern of blood vessels (vascular pattern). Depending of the severity of UC various abnormalities are seen in the mucosal appearance of the Colon.
In mild cases only some edema (swelling) and loss of vascular pattern maybe seen, whereas in severe cases there is extensive ulceration and spontaneous bleeding from the mucosal surface.
The extent of involvement may differ in every patient. Only consistent finding is that Colon is universally involved and small intestine is spared. Based on the extent of involvement, the doctor may classify your disease into following types
- Proctitis (only rectum involved)
- Proctosigmoiditis (rectum and sigmoid colon involved)
- Left sided Colitis/Distal Colitis (rectum, sigmoid and descending colon involved)
- Pancolitis (Disease extension beyond descending colon)
Is biopsy necessary for diagnosis of UC?
Biopsy involves taking a small piece of tissue from the mucosa with specialised instruments which are passed through a dedicated channel in the Colonoscope. It is painless and patient may not even realise that it has been done. Biopsy is hardly associated with any significant complications and is an innocuous procedure. The obtained tissue is then examined under the microscope to see finer tissue architecture which is not possible for the naked human eye.
Colonoscopy appearance of UC is characteristic and may not always need biopsy for confirmation. However, in certain scenarios the doctor may insist on getting a tissue biopsy as well. Few examples include first presentation of disease when it is done especially to rule out infectious causes of Colitis, if patient is not responding to treatment to see for super added infections, to see for early cancer from areas with suspicious appearance etc.