Summary

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) affecting the colon and rectum. Unlike Crohn's disease, inflammation in UC is confined to the mucosa and is continuous, starting from the rectum and extending proximally. Disease extent is classified as proctitis, left-sided colitis, or extensive/pancolitis. Clinical features include bloody diarrhoea, urgency, and tenesmus. Severity is assessed using the Truelove and Witts criteria. Treatment involves 5-aminosalicylates (5-ASA) for mild-moderate disease, corticosteroids for flares, and immunomodulators or biologics for steroid-dependent or refractory disease. Unlike Crohn's, panproctocolectomy is curative.

Key Facts

• Definition: Chronic mucosal inflammation of colon and rectum
• Location: Colon only; continuous from rectum
• Pattern: Continuous inflammation, mucosal only
• Histology: Crypt abscesses, goblet cell depletion, pseudopolyps
• Key Symptom: Bloody diarrhoea with mucus
• Treatment: 5-ASA (mild-moderate), steroids (flares), biologics (refractory)
• Surgery: Curative (panproctocolectomy with ileoanal pouch or end ileostomy)

Clinical Pearls

"UC = Colon Only, Continuous, Mucosal": Distinguishes from Crohn's.

"5-ASA is King in UC": 5-aminosalicylates are first-line for induction and maintenance in mild-moderate UC (unlike Crohn's where they have limited role).

"Truelove-Witts for Severity": Classic criteria for assessing acute severe colitis — bloody stools ≥6/day + systemic signs.

Why This Matters Clinically

UC is a common, lifelong condition with significant morbidity. Acute severe colitis is a medical emergency requiring inpatient management. Colorectal cancer surveillance is essential due to increased long-term risk.

Structured Approach

General:

• Nutritional status
• Pallor, dehydration
• Fever, tachycardia

Abdominal:

• Tenderness (diffuse or left-sided)
• Distension (toxic megacolon)
• Bowel sounds (may be reduced)

PR Examination:

• Blood, mucus
• Proctitis signs

Extra-Intestinal:

• Joints, skin, eyes

Natural History

Most patients have relapsing-remitting disease. ~20% have a severe first attack. 10-15% require colectomy within 10 years.

Outcomes

Key Guidelines

1. NICE NG130: Ulcerative Colitis (2019) — UK pathway.

2. ECCO Guidelines on UC (2022) — European consensus.

Landmark Trials

ACT 1 & 2 (2005) — Infliximab in UC

• Key finding: Infliximab effective for moderate-severe UC
• Clinical Impact: Established anti-TNF in UC

OCTAVE Trials (2017) — Tofacitinib

• Key finding: JAK inhibition effective in UC
• Clinical Impact: Oral small molecule therapy option

Evidence Strength

What is Ulcerative Colitis?

Ulcerative colitis is a type of inflammatory bowel disease that causes inflammation and ulcers in your large bowel (colon) and rectum. It causes diarrhoea (often bloody) and an urgent need to go to the toilet.

What causes it?

The exact cause isn't known, but it involves your immune system attacking your gut lining. Genes, environment, and gut bacteria all play a role.

What are the symptoms?

• Bloody diarrhoea
• Mucus in stool
• Urgency to open bowels
• Crampy tummy pain
• Tiredness

How is it treated?

1. 5-ASA medicines (mesalazine): First-line for mild-moderate disease
2. Steroids: For flare-ups
3. Immune-modifying drugs: Azathioprine for maintenance
4. Biological medicines: Injections for severe disease
5. Surgery: Removing the colon is curative if medicines don't work

What to expect

• UC is a lifelong condition with flares and remissions
• Most people can live normal lives with treatment
• Regular colonoscopies are needed to check for bowel cancer
• Surgery can cure UC but means having a stoma or internal pouch

When to seek help

See your doctor urgently if:

• You have more than 6 bloody stools per day
• You have a fever or feel very unwell
• You have severe abdominal pain or bloating
• You feel dizzy or faint