Ulcerative colitis (UC) is a chronic, relapsing-remitting, inflammatory disease which affects the large bowel and rectum. It is the most common form of inflammatory bowel disease (IBD), an umbrella term encompassing two chronic idiopathic inflammatory conditions; UC and Crohn’s disease (CD).1
Although UC can be diagnosed at any age, its’ incidence is often described as being bimodal (15-30 years and 50-70 years).2
Anatomy and pathophysiology
The exact underlying aetiology of UC remains unclear, however, there is some evidence that the combination of an altered intestinal microbiota and compromised colonic epithelial integrity, results in the inappropriate exposure of non-sterile intestinal contents to the underlying immunological tissue causing inflammation. Genetic, environmental and dietary factors have all been suggested to have an important role in disease pathogenesis.3
Important risk factors for UC include:4
Family history of IBD
Recent gastrointestinal infection
Smoking cessation (overall benefits of smoking cessation still outweigh the risk of UC)
Ashkenazi Jewish descent
Typical symptoms of UC include:3
Diarrhoea ± blood ± mucus
Lower abdominal pain
Abdominal discomfort and bloating
Other symptoms may relate to extra-intestinal manifestations of UC:5
Other diagnoses with similar clinical features that are important to consider include:4
Irritable bowel syndrome (IBS): this is an important diagnosis of exclusion
A diagnosis of UC is predominantly made based on features of the clinical history and endoscopic findings. However, it is important that other causes of colitis and diarrhoea, both infectious and non-infectious, are ruled out before a diagnosis of UC is made.
Blood tests 7
Blood tests relevant to the investigation of UC include:
FBC: anaemia, raised WCC
LFTs: hypoalbuminaemia (severe disease)
pANCA (if PSC is suspected)
Stool tests relevant to the investigation of UC include:
Faecal calprotectin is significantly raised in UC, as it is a marker of intestinal inflammation (useful for distinguishing between IBS and IBD)
Microscopy and culture: important for the exclusion of infection (e.g. Salmonella, E.coli, Campylobacter)
Endoscopy is the gold standard investigation for the diagnosis of UC.4
Sigmoidoscopy ± colonoscopy (and biopsy)
A flexible sigmoidoscopy is usually sufficient, due to the distal nature of UC, however, a full colonoscopy may be required if findings on sigmoidoscopy are unclear. A colonoscopy must be avoided in acute severe disease due to the increased risk of bowel perforation.
Continuous, uniformly inflamed mucosa
Erythematous, friable mucosa
Abnormal vascular pattern
Inflammatory polyps (‘pseudopolyps’)
Microscopic findings (biopsy):
Decreased goblet cell abundance
Additional imaging modalities
Additional imaging modalities such as plain abdominal X-ray (AXR) and computed tomography (CT) may be important for the exclusion of UC complications in an acute presentation (e.g. toxic megacolon, bowel perforation).
The two main aspects of management include the induction of remission and maintenance of remission.
Most patients are managed with optimal medical therapy which is escalated in a stepwise fashion, dependent on disease severity and symptom control. However, severe disease and uncontrollable flare-ups are likely to necessitate surgical intervention.
Treatment should be tailored to individuals, based on the severity and extent of disease, with the ultimate aim of improving quality of life and minimising the risk of complications.
Aminosalicylates (e.g. Mesalazine)
Mesalazine-5-aminosalicylic (5-ASA) is the current first-line treatment of choice for induction and maintenance of remission of mild-to-moderate ulcerative colitis.
There are both topical and oral preparations which can be used simultaneously if required.
Corticosteroids (e.g. Prednisolone)
Corticosteroids are typically used to induce remission in relapses of ulcerative colitis.
Unlike 5-ASA, corticosteroids are not used to maintain remission.
Thiopurines (e.g. Azathioprine) are typically used as a steroid-sparing therapy (e.g. to reduce steroid-related side effects) to induce and maintain remission.
Before azathioprine treatment, patients must have thiopurine methyltransferase (TPMT) activity checked, as reduced or absent activity increases the risk of myelosuppression.
Biological therapies are typically used when UC is refractory to other treatments.
Some examples of biologics used in the treatment of UC include:
Anti-TNFa (e.g. Infliximab)
Anti-IL-12/23 (e.g. Ustekinumab)
Anti a4b7 (e.g. Vedolizumab)
Surgery is predominantly reserved for patients in whom UC cannot be adequately controlled by optimal medical treatment or upon the occurrence of severe complications (e.g. toxic megacolon, bowel perforation).
Subtotal colectomy involves resection of part of the colon. Patients are likely to have a temporary de-functioning loop ileostomy, which can later be reversed, in order to protect the site of anastomosis.
Complete proctocolectomy involves the resection of the entire colon and rectum. Patients do not undergo further anastomotic surgery and thus have a permanent ileostomy.
Restorative proctocolectomy involves resection of the entire colon and rectum and a temporary loop ileostomy, which is later reversed with further surgery involving the joining of the ileal pouch to the anal canal (ileal pouch-anal anastomosis, IPAA).
Complete proctocolectomy with IPAA is the procedure of choice.
Untreated or poorly managed UC can result in various complications, including:4
Colorectal cancer: Individuals with a long history of UC are offered colonoscopic surveillance due to their increased risk of malignancy. Frequency of surveillance is dependent on individual patient risk (low, intermediate, high).
UC is the most common type of inflammatory bowel disease and has a relapsing-remitting course.
Common symptoms of UC include episodic diarrhoea with urgency, rectal bleeding and abdominal pain.
Extra-intestinal manifestations include; erythema nodosum, uveitis and joint pain.
Topical and oral aminosalicylates are the mainstay therapies used in UC.
Surgical intervention should not be delayed for urgent indications and usually involves partial or complete resection of the colon.
UC increases the lifetime risk of colorectal cancer and thromboembolic events.
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