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Ulcerative Colitis


Definition of ulcerative colitis

  • An autoimmune chronic inflammatory disease of the colon and rectum, with a relapsing-remitting pattern


Epidemiology of ulcerative colitis

  • Incidence about  10 per 100,00 per year
  • Prevalence is about 1 per 1000
  • Slightly more prevalent in men
  • More prevalent in northern hemisphere western countries


Causes and risk factors for ulcerative colitis

  • Thought to be a combination of environmental and genetic triggers
  • Monozygotic twin concordance rate of 10%
  • Smoking is protective (unlike Crohn’s)


Presentations of ulcerative colitis

  • Gastrointestinal
    • Bloody diarrhoea (maybe with mucus)
    • Lower abdominal discomfort
    • Abdominal tenderness
    • Palpable masses
    • Abdominal distension (can be indicative of toxic megacolon)
    • Urgency and frequency of stools (especially in acute attacks)
    • Tenesmus
  • Systemic
    • Malaise, lethargy, anorexia
  • Extra-intestinal manifestations
    • Erythema nodosum
    • Uveitis/episcleritis
    • Arthropathy
    • Pyoderma granulosum
    • Primary sclerosing cholangitis (75% of PSC is seen in UC patients)
  • NB. In an acute attack the patient may be pale, febrile, dehydrated, tachycardic and hypotensive


Differential diagnosis of ulcerative colitis

  • Infectious diarrhoea
    • Shigella, Salmonella, Campylobacter, E.coli, amoebae, Clostridium difficile
  • Crohn’s disease
  • Ischaemic colitis
  • Radiation enteritis
  • Chemical colitis
  • CMV colitis
  • GI malignancy
  • Coeliac disease
  • Irritable bowel syndrome


Pathology of ulcerative colitis

  • Macroscopic pathology
    • Inflammation extends proximally from the rectum (unlike Crohn’s, where the inflammation can be anywhere)
    • Hence inflammation can be classified as proctitis (limited to rectum), left-sided colitis (extending to sigmoid and descending colon), or pan-colitis (when entire colon involved)
    • Mucosa is reddened, inflamed, and bleeds easily.
    • Extensive ulceration, with islands of normal mucosa
  • Microscopic pathology
    • Superficial inflammation of mucosa (unlike Crohn’s, which is full-thickness)
    • Chronic inflammatory cell infiltrate in lamina propria (part of mucosa just under epithelium)
    • Crypt abcesses
    • Goblet (mucus-making) cell depletion


Video on the pathophysiology of IBD


Acute management of ulcerative colitis


  • Calculate severity according to Truelove and Witts’ criteria:
    • More than 6 bloody stools per day (often nocturnal) and at least one of:
      • Temp >37.8 on 2 out of 4 days
      • Hb <10.5
      • ESR >30
      • Pulse >90
      • Colon dilated >5.5cm
  • Immediate investigations
    • Bloods
      • FBC, U&E, LFT, CRP, ESR, coagulation, G&S
      • B12, folate, iron studies
      • Amylase and beta-HCG
      • Consider TPMT levels (see below)
    • Cultures
      • Blood culture
      • Stool  culture
    • Imaging
      • AXR: Check for megacolon: >5.5 cm dilated.
      • USS and CT
  • Supportive management
    • IV fluids (replace deficit followed by maintenance fluids)
    • Thromboprophylaxis (e.g. prophylactic LMWH)
    • Stool chart
    • Weigh daily
    • Assess nutritional status: if deplete then enteral feeding is preferable
    • No role for being NBM and can increase lactose intolerance
  • Flexible sigmoidoscopy
    • Should be undertaken within 72 hours (ideally 24h) to obtain diagnostic biopsy and to exclude CMV colitis.
  • Treatment
    • Steroids
      • 60mg po Prednisolone or 400mg iv hydrocortisone (100mg four times daily) for up to five days
      • There is no benefit in steroid therapy beyond 10 days.
    • Avoid antibiotics unless clear evidence of infection
    • Surgery
      • If any evidence of toxic megacolon (dilatation >5.5cm or caecum >9cm) then consider urgent colectomy depending on the clinical state of the patient.
      • A stool frequency >8/day or CRP >45 at 3 days predicts the need for colectomy in about 85% of cases.
      • Consider rescue therapy or colectomy if no improvement or deterioration at day three
  • Rescue therapy
    • Ciclosporin (2mg/kg/day)
      • Check magnesium, cholesterol and creatinine
      • Watch out for toxicity
      • Following remission, continue oral ciclosporin for 3-6 months
    • Infliximab
      • Check LFT, Hep B/C, HIV, varicella, TB (CXR or consider ELIZA)
        • No evidence for Hep C reactivation
      • Ensure vaccinations up to date (but no live vaccines)
      • Used as a bridge to further immunosuppressive drugs and not to maintain remission as evidence is limited.
    • If no response to rescue therapy is seen within 4-7 days then colectomy is recommended.


Further management of ulcerative colitis and maintenance of remission

  • Recommendations
    • Long term maintenance therapy is recommended for most patients, especially those with extensive or left-sided disease or those with proctitis who relapse more than once per year
  • Medical maintenance for UC
    • Patients should receive maintenance therapy with aminosalicylates, azathioprine or mercaptopurine
    • NICE does not recommend long-term use of anti-TNF therapy
    • Oral mesalazine 1.2-2.4g daily should be first-line
    • Topical mesalazine +/- oral can be used in patients with distal disease
    • Azathioprine 2-2.5mg/kg/day or mercaptopurine are the first-line agents for steroid-dependent disease
      • Long-term treatment with steroids is not acceptable
    • All patients should have thiopurine methyltransferase levels (TPMT) measured before starting thiopurines (metcaptopurine and azathioprine) to avoid fatal administration to those with no or low TPMT levels.
    • Methotrexate can be considered in patients who do not respond to above treatments
  • Surgery
    • Indications
      • Severe attacks which don’t respond to medical treatment or toxic megacolon (>5.5cm on AXR, thin-walled, thumb-printing, gas in bowel wall)
      • If toxic dilatation and no response to steroids over 24 hours, go straight to colectomy as perforation rates >30%
      • Poorly-controlled disease
      • Recurrent acute-on-chronic disease
      • Presence of dysplasia or carcinoma
    • Subtotal colectomy with ileostomy, with the option of returning later for a re-anastomosis and ileo-anal pouch formation.
    • Colectomy may also be considered in chronic disease due to poor response to medication, excessive steroid requirements or risk of cancer.


Complications of ulcerative colitis

  • Acute
    • Toxic megacolon
      • Mortality approximately 20%
  • Chronic
    • Primary sclerosing cholangitis (see PSC page)
    • Colorectal carcinoma
      • Risk increased 10-20 times once patients have had UC for 20 years
      • 5-asa treatment seems to reduce risk
      • Start screening colonoscopy at 10 years, then repeat at 1,3,or 5-year intervals depending on risk
      • Mucosal dysplasia on rectal biopsy is associated with cancer elsewhere in the bowel.
    • Pouchitis after colectomy (with relapsing-remitting course)
    • Osteoporosis from steroid therapy
      • Hence give bisphosphonates to over 65s on steroids
      • DEXA, then bisphosphonates if T<1.5 if not over 65


Prognosis of ulcerative colitis

  • With treatment, mortality only slightly more than normal population and that is mostly in the first two years after diagnosis
  • 10% need colectomy in first year, 14% will have colectomy at 20 years
  • 50% will relapse in any one year
  • 90% get back to normal employment after 1 year


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