Ulcerative colitis

Introduction

Ulcerative colitis (UC) is a chronic relapsing-remitting inflammatory bowel disease (IBD) characterised by superficial inflammation and ulceration of the colonic mucosa. The inflammation is continuous, starts in the rectum, and extends proximally—never affecting the small bowel beyond the ileocaecal valve.

Peak Incidence

• Primary peak: 15–30 years of age.
• Secondary peak: 50–70 years of age.

Pathophysiology

• The exact cause is unclear but likely involves:
  • Genetic predisposition.
  • Dysregulated immune response to gut microbiota.
  • Environmental triggers.
• The disease is confined to the mucosa and submucosa of the colon.
• Rectal involvement is universal, and inflammation may extend to involve the entire colon (pancolitis).

Symptoms

Gastrointestinal

• Bloody diarrhoea (with or without mucus).
• Urgency and tenesmus – Indicative of rectal inflammation.
• Lower abdominal cramping or pain (typically left-sided).

Systemic

• Fatigue.
• Weight loss (in more severe cases).

Extraintestinal Manifestations

• Musculoskeletal: Arthritis, ankylosing spondylitis.
• Ocular: Uveitis, episcleritis.
• Dermatological: Erythema nodosum, pyoderma gangrenosum.
• Hepatobiliary: Primary sclerosing cholangitis (PSC).

Signs

• Lower left quadrant tenderness.
• Pallor – Due to anaemia.
• Tachycardia – In severe disease or anaemia.
• Fever – In active or severe flares.
• Perianal findings – May include skin tags, but less common than in Crohn’s disease.

Diagnosis

Blood Tests

• FBC: May show anaemia (normocytic or iron deficiency).
• CRP / ESR: Raised during active inflammation.
• Faecal calprotectin: Marker of intestinal inflammation.
• Stool cultures: To exclude infections (e.g. Clostridioides difficile, Giardia).

Imaging and Endoscopy

• Colonoscopy with biopsy (Gold standard):
  • Continuous mucosal inflammation.
  • Endoscopic findings: Loss of vascular pattern, friability, ulcerations.
  • Histology: Crypt abscesses, basal plasmacytosis.
• Abdominal X-ray: To exclude complications such as toxic megacolon (colonic diameter >6 cm).
• CT/MRI: May assist in assessing complications or ruling out differential diagnoses (e.g. Crohn’s).

Severity Classification – Truelove and Witts Criteria

Complications

• Anaemia – Due to chronic blood loss.
• Malnutrition – Especially in extensive disease.
• Perforation – From deep ulceration.
• Toxic megacolon – Acute colonic dilation (>6 cm); life-threatening.
• Colorectal cancer – Risk increases after 8–10 years of disease.

Management

Lifestyle and Supportive Measures

• High-fibre diet – May be helpful in remission (not during flares).
• Avoid:
  • NSAIDs, alcohol, high-fat processed foods.
• Probiotics – May have a modest role in maintenance.

Acute Flare Management

Mild to Moderate Disease

• First-line: Oral and/or rectal 5-ASA (mesalazine).
• Alternative: Budesonide-MMX for left-sided colitis.

Moderate to Severe Disease

• Systemic corticosteroids:
  • Oral prednisolone 40–60 mg/day.
  • IV hydrocortisone for hospitalised patients.
• Steroid-sparing agents:
  • Thiopurines – Azathioprine or 6-mercaptopurine (for steroid-dependent cases).
  • Biologics – Anti-TNF agents (e.g. infliximab, adalimumab).
  • JAK inhibitors (e.g. tofacitinib) – For refractory cases.

Fulminant Colitis

• IV corticosteroids + biologics.
• Surgical referral if no response.

Maintenance Therapy

• Mild Disease: Oral/rectal 5-ASA.
• Moderate to Severe Disease: Thiopurines or biologics (e.g. anti-TNF, vedolizumab).
• Goal: Achieve and maintain steroid-free remission.

Surgical Management

Indications

• Refractory disease – Failure of medical therapy.
• Severe complications – Perforation, toxic megacolon, uncontrolled bleeding.
• Cancer prevention – In high-risk or dysplasia cases.

Procedure

• Total proctocolectomy with ileal pouch–anal anastomosis (IPAA) – Preferred curative surgery.

Surveillance

• Colonoscopy every 1–2 years starting 8–10 years after diagnosis.

• More frequent if:

  • Family history of colorectal cancer.
  • Coexisting PSC.
  • Extensive colitis.