Ulcerative Colitis

🔍 When to Suspect

The cardinal symptom is visible bloody diarrhoea, present for ≥6 weeks, often with rectal urgency, tenesmus, and cramping abdominal pain

From the full topic in The Ocean Library: Ulcerative Colitis

🧭 When to suspect

Ulcerative colitis (UC) is a chronic, relapsing–remitting inflammatory bowel disease in which continuous mucosal inflammation extends proximally from the rectum for a variable distance:

• From proctitis alone

• Through left-sided disease

• To extensive colitis or pancolitis

Inflammation is confined to the colon and is limited to the mucosa and submucosa, which is what distinguishes it from the transmural, patchy, mouth-to-anus pattern of Crohn's disease.

Suspect UC in anyone with diarrhoea containing visible blood or mucus persisting for more than 6 weeks, typically with:

• Rectal urgency

• Tenesmus

• Crampy left lower quadrant pain

Nocturnal diarrhoea and rectal bleeding point strongly to organic disease and help separate UC from irritable bowel syndrome.

A raised faecal calprotectin supports inflammation and is the key primary-care test for triaging who needs gastroenterology referral.

Be alert to extra-intestinal manifestations, which may precede or accompany bowel symptoms:

• Arthropathy

• Erythema nodosum

• Episcleritis/uveitis

• Aphthous ulcers

Two priorities:

• Assess disease severity using the Truelove and Witts' criteria

• Never miss acute severe colitis or toxic megacolon, which are medical emergencies

Drug choice for induction and maintenance is then driven largely by disease extent.

Truelove & Witts	Mild	Moderate	Severe
Bloody stools per day	Fewer than 4	4 to 6	6 or more, plus ≥ 1 systemic feature below
Temperature	Normal	Normal	> 37.8°C
Pulse	Normal	Normal	> 90 bpm
Haemoglobin	Normal	Normal	Anaemia (Hb < 105 g/L)
ESR (CRP often used)	30 or below	30 or below	Above 30 mm/hr

An acute severe flare – ≥ 6 bloody stools per day with any systemic feature – mandates emergency admission for intravenous corticosteroids, not outpatient management.

Source: NICE NG130 · NICE DG11 · BSG IBD 2025

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