IBD - Ulcerative Colitis

Question 1

How common is it?

Answer 1

Incidence = 10-2/100,000/yr. 
Prevalence = 100-200/100,000

Question 2

Who does it affect?

Answer 2

1:1 M:F ratio. Most present aged 15-30 yrs. 3-fold as common in non-smokers – symptoms may relapse on stopping smoking.

Question 3

What causes it?

Answer 3

• A relapsing inflammatory disorder of the colonic mucosa. May just affect the rectum or extend to affect some or all of the colon. Never spreads proximal to ileocaecal valve.
• Cause unknown. Some genetic susceptibility.

Question 4

Risk factors?

Answer 4

Most unknown. Age, race (white people at greater risk), family history.

Question 5

How does it present?

Answer 5

Pathology – Hyperaemic/haemorrhagic granular colonic mucosa ± pseudopolyps formed by inflammation. Punctate ulcers may extend deep into Lamina Propria – inflammation is normally not transmural. Mucosal disease differentiates it from Crohn’s.

Symptoms – episodic or chronic diarrhoea (± blood and mucus); crampy abdominal discomfort; bowel frequency relates to severity; urgency/tenesmus = rectal UC. Systemic symptoms in attacks: fever, malaise, anorexia, weight loss.

Signs – May be none. In acute, severe UC there may be fever, tachycardia and a tender distended abdomen.
Extraintestinal signs – clubbing, aphthous oral ulcers, erythema nodusum, pyoderma gangrenosum, conjunctivitis, episcleritis, irits, large joint arthritis, sacrolitis, ankylosing spondylitis, fatty liver, cholangiocarcinoma, nutritional deficits, amyloidosis.

Question 6

Other conditions with similar presentation?

Answer 6

• The main differential is Crohn’s disease which has very similar clinical features.
• Prolonged use of laxatives.
• Infective colitis (chronic schistosomiasis, amoebiasis,tuberculosis).
• Mild colitis may mimic irritable bowel syndrome.
• Other conditions which occasionally cause diagnostic difficulty include:
• Ischaemic colitis
• Radiation colitis
• Bowel trauma
• Colorectal cancer
• Diverticulitis
• Polyposis syndromes
• Colonic polyps

Question 7

Investigations?

Answer 7

• Bloods – FBC, ESR, CRP, U&E, LFT, blood culture.
  Stool MC&S/CDT – to exclude campylobacter, c. difficile, salmonella, shigella, E.coli, amoebae.
• AXR – No faecal shadows, mucosal thickening/islands, colonic dilatation.
• Erect CXR – Perforation.
• Ba enema – never do during severe attacks or for diagnosis.
• Colonoscopy – shows extent and allows biopsy – look for inflammatory infiltrate; goblet cell depletion; glandular distortion, mucosal ulcers, crypt abscesses.

Question 8

Treatments?

Answer 8

• Mesalazine-5-aminosalicylic acid (5-ASA) (Aminosalicylate) is now the treatment of choice for induction and maintenance of remission of mild-to-moderate ulcerative colitis.
• Corticosteroids are used to induce remission in relapses of ulcerative colitis. They have no role in maintenance therapy.
• Ciclosporin is an effective salvage therapy for patients with severe refractory colitis and it has a rapid onset of action.
• Infliximab is effective in inducing clinical remission in patients with moderate-to-severe ulcerative colitis, whose disease is refractory to conventional treatment using corticosteroids and/or immunosuppressive agents.
• Surgery required in ~20% cases. Eg. Proctocolectomy + terminal ileostomy. Colectomy with ileo-anal pouch later.
• Immunomodulation is another alternative if no remission comes with steroids or prolonged use required.