Makindo Medical Notes

Related Subjects: |Acute Severe Colitis |Ulcerative Colitis |Microscopic colitis |Irritable bowel syndrome |Lower Gastrointestinal (Rectal) Bleeding

Ulcerative Colitis

Ulcerative colitis is a relapsing-remitting inflammatory disease of the colon associated with an increased risk of colorectal cancer. It may also lead to acute severe colitis, requiring urgent management.

About

• Ulcerative colitis (UC) is a chronic, relapsing-remitting inflammatory bowel disease (IBD) affecting the colon and rectum.
• UC is more common than Crohn's disease, with an incidence of 10-20 per 100,000 and a prevalence of 50-100 per 100,000.
• Commonly affects Caucasians and Jewish populations, particularly in the US and Europe.

Aetiology

• Thought to be triggered by an abnormal immune response to environmental factors.
• Interestingly, smoking and appendicectomy appear to be protective factors against UC.
• Increased prevalence of pANCA (perinuclear anti-neutrophil cytoplasmic antibodies) is observed.
• Systemic complications like primary sclerosing cholangitis (PSC) are more common in UC.

Extent of Disease

Ulcerative colitis typically begins in the rectum and may extend proximally in a continuous manner. Disease extent can influence symptoms, treatment, and cancer risk.

Clinical Presentation

• Diarrhoea: Often contains mucus and blood, with frequency ranging from mild to severe (10-20 stools/day in acute cases).
• Urgency and incontinence due to rectal inflammation.
• Flare-ups can be provoked by infections, stress, NSAIDs, or antibiotics.
• Other symptoms include crampy abdominal pain, weight loss, and fever.

Extraintestinal Manifestations

• Skin: Erythema nodosum, pyoderma gangrenosum.
• Eyes: Conjunctivitis, iritis, episcleritis.
• Joints: Migratory arthritis, sacroiliitis, ankylosing spondylitis (common in Crohn's).
• Mouth ulcers, clubbing, and hepatobiliary involvement (e.g., primary sclerosing cholangitis).
• Other: Venous thromboembolism, amyloidosis, and increased risk of colorectal cancer.

Pathology

• UC affects the colon and rectum only, beginning distally (proctitis) and extending proximally in a continuous pattern.
• Histological features include goblet cell depletion, crypt abscesses, and pseudopolyps.
• Inflammation is confined to the mucosal layer, with no transmural involvement.
• In long-standing disease, loss of haustra and atrophic, featureless bowel are common, along with an increased malignancy risk.

Assessing Severity (Modified Truelove and Witts' Criteria)

Investigations

• Blood tests: FBC (anaemia), U&E (dehydration), CRP/ESR (inflammation), LFTs (liver disease), and pANCA (positive in 70% of cases).
• Faecal calprotectin: Elevated in active inflammation.
• Imaging:
  • AXR: Can show toxic megacolon (diameter > 6 cm) and mucosal oedema (thumbprinting).
  • Sigmoidoscopy: Shows inflamed, erythematous mucosa with biopsy potential.
  • Colonoscopy: Useful for disease extent and surveillance but avoided in acute flares.
  • Barium enema: Shows haustral loss and a featureless colon; avoid during acute flare.

Management

• Mild disease:
  • Mesalazine (500 mg qds) or Sulfasalazine (1g bd) with rectal Mesalazine for distal disease.
  • Short course of Prednisolone (20 mg) tapered over 2 weeks may be added.
• Moderate disease:
  • Prednisone (40-60 mg) tapered over a month; Mesalazine (Pentasa) may be used concurrently.
  • Steroid enemas for proctosigmoiditis.
• Severe disease:
  • Requires hospital admission with IV fluids, IV Hydrocortisone, and close monitoring.
  • Consider IV Ciclosporin or Infliximab if no response to high-dose steroids after 3-5 days to reduce the need for surgery.
• Toxic Megacolon:
  • Life-threatening complication requiring gastroenterology and surgical input.
  • IV Methylprednisolone, nutritional support, VTE prophylaxis, and twice-daily abdominal circumference monitoring.
  • Urgent colectomy may be necessary if no improvement after 3-5 days.
• Elective Surgery:
  • Panproctocolectomy with ileal pouch-anal anastomosis (curative but with increased stool frequency).
  • May reduce long-term cancer risk but risk of pouchitis remains.

Other Treatment Options

• Immunosuppressants: Azathioprine and Mercaptopurine as steroid-sparing agents; require close FBC monitoring due to risk of bone marrow suppression and pancreatitis.
• Biologics: Infliximab (anti-TNF) and other biologics are reserved for severe cases.
• Ciclosporin: Used in acute severe cases not responding to IV steroids.

Additional Support

• Nutritional support: Dietitian involvement to maximise nutrition and support weight maintenance.
• Nurse specialist: Provides ongoing support, particularly for managing flare-ups and medication adherence.

Step-Up Therapy in Ulcerative Colitis

References

• NICE Guideline on Ulcerative Colitis