🔥 Ulcerative colitis (UC) = a relapsing-remitting inflammatory disease of the colon, starting in the rectum and spreading continuously. ⚠️ Risks: acute severe colitis (medical emergency) + ↑ risk of colorectal cancer.

📖 Overview

Chronic inflammatory bowel disease (IBD) limited to colon & rectum.
Incidence ~10–20/100,000; prevalence 50–100/100,000. More common than Crohn’s.
Peak onset 20–40 years; higher prevalence in Caucasian & Jewish populations.

🧬 Pathophysiology & Etiology

Dysregulated immune response to gut microbiota in genetically susceptible individuals.
⚡ Protective factors: smoking & prior appendicectomy.
Autoantibodies: pANCA often positive.
Association: Primary Sclerosing Cholangitis (PSC).
Mucosal-only inflammation; continuous from rectum → proximal colon.

📊 SCCAI: Simple Clinical Colitis Activity Index

SCCAI is a symptom-based score used to assess ulcerative colitis activity.
It is useful in clinic because it is quick and does not require endoscopy or blood tests.
It assesses stool frequency, urgency, bleeding, general wellbeing and extra-intestinal features.
A score of ≤2 usually suggests remission and a score of ≥5 suggests active disease.

Domain	What is assessed
Daytime stool frequency	Number of bowel motions during the day.
Nocturnal stool frequency	Whether the patient wakes at night to open bowels.
Urgency	Urgency, hurry, incontinence or inability to defer defaecation.
Rectal bleeding	None, trace, occasional frank blood, or usually frank blood.
General wellbeing	Very well through to terrible.
Extra-intestinal features	Arthritis, uveitis, erythema nodosum, pyoderma gangrenosum etc.

🧠 Teaching point: SCCAI measures clinical disease activity, not mucosal healing. A patient can feel better while still having active inflammation, so faecal calprotectin, CRP and endoscopy may still be needed depending on the context.

🩺 Clinical Features

💩 Bloody diarrhoea ± mucus; urgency, tenesmus, incontinence.
🤒 Systemic symptoms in severe disease: fever, tachycardia, weight loss.
⚡ Flare triggers: infections, NSAIDs, antibiotics, stress.
Extra-intestinal: skin (erythema nodosum, pyoderma gangrenosum), eyes (iritis, episcleritis), joints (arthritis, sacroiliitis), liver (PSC), mouth ulcers, clubbing, ↑ VTE risk.

📊 Severity Assessment (Modified Truelove & Witts)

Severity	Features
🙂 Mild	<4 bloody stools/day; no systemic upset; Hb >115; CRP <5
😐 Moderate	4–6 stools/day; mild systemic disturbance; Hb >105; CRP <30
😟 Severe	>6 bloody stools/day + systemic features (T >37.8°C, HR >90, Hb <105, CRP >30)
🚨 Fulminant	≥10 stools/day, continuous bleeding, severe toxicity, colonic dilatation on AXR

🔎 Investigations

🩸 Bloods: FBC, CRP/ESR, U&E, LFTs, pANCA.
💩 Faecal calprotectin: marker of active inflammation.
📷 Imaging: AXR (toxic megacolon), sigmoidoscopy (preferred in flare), colonoscopy (extent, surveillance), avoid full colonoscopy in acute flare.

💊 Drug Management (NICE NG130)

Drug Class	Examples / Dose	Indication / Notes
5-ASA 🟢	Oral Mesalazine 2–4 g/day; Sulfasalazine 2–4 g/day; Rectal 5-ASA enemas 1 g/night	Mild–moderate UC; combine oral + rectal for extensive disease; monitor renal function
Topical steroids 💠	Budesonide MMX 9 mg OD; Hydrocortisone enemas 100 mg/day	Mild–moderate distal colitis; fewer systemic effects
Oral corticosteroids 🌟	Prednisolone 40–60 mg OD, taper 8–12 weeks	Moderate–severe flare; monitor BP, glucose, infection risk, bone health
IV corticosteroids 🚑	Hydrocortisone 100 mg QDS; Methylprednisolone 60 mg OD	Acute severe UC; assess response at 3–5 days → rescue therapy if refractory; supportive care essential
Immunomodulators 🛡️	Azathioprine 2–2.5 mg/kg/day; 6-Mercaptopurine 1–1.5 mg/kg/day	Maintenance/steroid-sparing; monitor FBC/LFTs; check TPMT activity before starting
Biologics / Anti-TNF 💉	Infliximab 5 mg/kg IV; Adalimumab SC; Vedolizumab 300 mg IV	Moderate–severe UC unresponsive to steroids/immunomodulators; screen TB/HBV; monitor response via CRP/fecal calprotectin
Ciclosporin IV ⚡	2 mg/kg/day IV → oral 5 mg/kg/day	Rescue therapy for steroid-refractory acute severe UC; bridge to azathioprine; monitor BP, renal function
Supportive 🧩	LMWH prophylaxis, antibiotics if infection, nutritional support	Reduces complications, optimises outcomes

🚨 Acute Severe UC (NICE-compliant)

Admit → IV fluids, IV hydrocortisone, nutritional support, VTE prophylaxis.
Monitor stool frequency, vitals, bloods, daily AXR.
No improvement at 3–5 days → rescue therapy (IV ciclosporin or infliximab) or colectomy.
Toxic megacolon → urgent surgery (subtotal colectomy).

🔪 Surgical Options

Panproctocolectomy + ileal pouch-anal anastomosis → curative, reduces cancer risk, but ↑ stool frequency, pouchitis risk.

🌱 Supportive & MDT Care

Dietitian → optimise nutrition.
IBD nurse specialist → flare management, medication counselling.
Psychological support if chronic disease impact.

💡 Teaching Pearls

UC = continuous mucosal inflammation starting at rectum (vs Crohn = skip lesions, transmural).
Acute severe colitis = medical emergency; IV steroids first, rescue biologics or colectomy if refractory.
Long-term risk: colorectal cancer → start surveillance after 8–10 years of disease.
Extra-intestinal features often parallel disease activity.
Step-up therapy mnemonic: 5-ASA → steroids → immunomodulator → biologics → surgery 🔄

Cases

Mild–moderate flare 👨‍🦱: 27-year-old man, bloody diarrhoea 6 weeks. Management: oral + rectal mesalazine, steroids if needed. Outcome: good response.
Severe acute colitis ⚡: 34-year-old woman, >10 bloody stools/day, fever, tachycardia, CRP 110. Management: admit, IV hydrocortisone, fluids, LMWH, rescue infliximab at 72h if no improvement. Outcome: improved, discharged on oral steroids + azathioprine.
Toxic megacolon 🚨: 45-year-old man, pancolitis, distension, shock. AXR: transverse colon >6 cm. Management: resuscitation, IV steroids, antibiotics, urgent subtotal colectomy. Outcome: recovered, later pouch surgery.

References 📚

NICE NG130 – Ulcerative Colitis

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Ulcerative Colitis ✅