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

• This is a medical emergency and patients with severe colitis should be admitted, ideally onto a gastrointestinal ward. See British Society of Gastroenterologists guidelines for further information

 

• 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

 

Click here for medical student OSCE and PACES questions about Ulcerative Colitis

Common Ulcerative Colitis exam questions for medical students, finals, OSCEs and MRCP PACES

 

Click here to download free teaching notes on Ulcerative Colitis: Ulcerative colitis

Perfect revision for medical students, finals, OSCEs and MRCP PACES