Download the amazing global Makindo app: ✅ Means NICE/National Guidelines 2026 compliant Android \| Apple

MEDICAL DISCLAIMER: Educational use only. Not for diagnosis or management. See below for full disclaimer.

Acute Severe Colitis

💊👩‍⚕️ Acute Severe Ulcerative Colitis / Acute Severe Colitis - Early Gastroenterology + Colorectal Surgery MDT
⚡ Assess severity using Truelove & Witts criteria: acute severe UC is typically ≥6 bloody stools/day plus systemic disturbance. 💦 Admit urgently: start IV fluids, correct electrolytes, especially potassium and magnesium, and monitor urine output. 💉 IV corticosteroids: give IV hydrocortisone 100 mg four times daily or equivalent; reassess response at 72 hours. 🦶 VTE prophylaxis: give LMWH unless contraindicated. Rectal bleeding alone is not usually a reason to omit prophylaxis; seek senior advice if bleeding is massive or haemodynamic instability is present. 🫀 Monitor closely: pulse, BP, temperature, oxygen saturations, stool frequency, blood loss, abdominal signs, fluid balance and urine output. 💩 Exclude infection: send stool culture and Clostridioides difficile testing; consider CMV, parasites or other pathogens in immunosuppressed or refractory cases. 🌡️ Watch systemic features: dehydration, tachycardia, fever, hypotension, anaemia, rising CRP, low albumin or acute kidney injury. ⚡ Look for toxic megacolon: abdominal distension, tenderness, guarding, systemic toxicity, shock, or colonic dilatation >6 cm on imaging. 🚨 Escalation / rescue: if no clear improvement by day 3, discuss rescue therapy and surgery with gastroenterology and colorectal surgery. 💊 Rescue therapy: NICE supports ciclosporin as standard rescue therapy; infliximab is an option when ciclosporin is contraindicated or clinically inappropriate. 🔪 Urgent colectomy: do not delay if toxic megacolon, perforation, uncontrolled bleeding, severe systemic compromise, or failure of medical rescue therapy.

💊👩‍⚕️ Acute Severe Ulcerative Colitis / Acute Severe Colitis - Early Gastroenterology + Colorectal Surgery MDT

⚡ Assess severity using Truelove & Witts criteria: acute severe UC is typically ≥6 bloody stools/day plus systemic disturbance.
💦 Admit urgently: start IV fluids, correct electrolytes, especially potassium and magnesium, and monitor urine output.
💉 IV corticosteroids: give IV hydrocortisone 100 mg four times daily or equivalent; reassess response at 72 hours.
🦶 VTE prophylaxis: give LMWH unless contraindicated. Rectal bleeding alone is not usually a reason to omit prophylaxis; seek senior advice if bleeding is massive or haemodynamic instability is present.
🫀 Monitor closely: pulse, BP, temperature, oxygen saturations, stool frequency, blood loss, abdominal signs, fluid balance and urine output.
💩 Exclude infection: send stool culture and Clostridioides difficile testing; consider CMV, parasites or other pathogens in immunosuppressed or refractory cases.
🌡️ Watch systemic features: dehydration, tachycardia, fever, hypotension, anaemia, rising CRP, low albumin or acute kidney injury.
⚡ Look for toxic megacolon: abdominal distension, tenderness, guarding, systemic toxicity, shock, or colonic dilatation >6 cm on imaging.
🚨 Escalation / rescue: if no clear improvement by day 3, discuss rescue therapy and surgery with gastroenterology and colorectal surgery.
💊 Rescue therapy: NICE supports ciclosporin as standard rescue therapy; infliximab is an option when ciclosporin is contraindicated or clinically inappropriate.
🔪 Urgent colectomy: do not delay if toxic megacolon, perforation, uncontrolled bleeding, severe systemic compromise, or failure of medical rescue therapy.

📖 About

⚠️ Acute severe ulcerative colitis is a potentially life-threatening flare of ulcerative colitis. It can also be considered within the broader emergency differential of acute severe colitis.
Major risks include toxic megacolon, perforation, haemorrhage, sepsis, venous thromboembolism, electrolyte disturbance, acute kidney injury and malnutrition.
🧬 Pathophysiology: severe mucosal inflammation causes bloody diarrhoea, fluid loss, protein loss, systemic inflammatory response and impaired colonic motility. In severe cases, neuromuscular dysfunction and inflammation can lead to toxic megacolon and perforation.
🫀 Systemic features: tachycardia, fever, hypotension, anaemia, raised inflammatory markers, hypoalbuminaemia and dehydration indicate severe disease and higher complication risk.

🧪 Aetiology / Differential Diagnosis

🔥 Inflammatory bowel disease flare: ulcerative colitis is the classic cause; Crohn’s colitis can also present with severe colitis.
🦠 Clostridioides difficile colitis: especially after antibiotics, hospital admission, PPI use or in older/frail patients.
🌍 Infectious colitis: bacterial causes include Salmonella, Shigella, Campylobacter and E. coli; parasitic causes include Entamoeba; viral causes include CMV in immunosuppressed patients.
💊 Drug-induced colitis: NSAIDs, immune checkpoint inhibitors and some chemotherapeutic/immunosuppressive agents.
🩸 Other important mimics: ischaemic colitis, diverticulitis, colorectal cancer and radiation colitis depending on age and context.

🩺 Clinical Examination Tips

🌡️ Vital signs: fever, tachycardia >90 bpm, hypotension, postural drop, tachypnoea or reduced urine output suggest systemic toxicity or hypovolaemia.
💩 Abdominal examination: assess tenderness, distension, guarding and peritonism. Peritonism suggests perforation or fulminant colitis and requires urgent surgical review.
🫀 Hydration status: capillary refill, mucous membranes, JVP, postural symptoms, urine output and lactate if shocked.
⚡ Red flags: sudden worsening pain, abdominal distension, rising CRP, falling haemoglobin, falling albumin, fever, tachycardia, shock, confusion or reduced urine output.
👵 Atypical presentations: older adults, frail patients and immunosuppressed patients may have less pain, low-grade fever, confusion, anorexia or subtle diarrhoea despite severe disease.

🔎 Assessment & Investigations

🧾 Assess severity: use Truelove & Witts criteria. Acute severe UC is usually ≥6 bloody stools/day plus at least one systemic marker, such as fever, tachycardia, anaemia, ESR >30 mm/h or CRP >30 mg/L.
📊 Bloods: FBC, U&E/creatinine, LFTs, magnesium, calcium, CRP, glucose, albumin, clotting and group & save if significant bleeding or surgery possible.
🧪 Stool tests: C. difficile PCR/toxin and stool culture. Consider ova/parasites, travel-related pathogens and CMV assessment in immunosuppressed or steroid-refractory patients.
🩻 Imaging: abdominal X-ray if severe pain, distension, systemic toxicity or suspected toxic megacolon. CT abdomen/pelvis if perforation, abscess, alternative diagnosis or complications are suspected. Chest X-ray may show free subdiaphragmatic air if perforation is suspected.
🔬 Endoscopy: consider early limited flexible sigmoidoscopy with biopsies to assess severity and exclude CMV, especially in steroid-refractory or immunosuppressed patients. Avoid full colonoscopy in acute severe colitis because of perforation risk.
🧬 Before rescue/maintenance therapy: screen for TB and hepatitis B/C before anti-TNF therapy where possible; check HIV/varicella status if relevant. Check TPMT/NUDT15 before thiopurines such as azathioprine, but do not delay urgent rescue decisions unnecessarily.

🛠️ Initial Management - Day 1 to Day 3

🏥 Admit urgently under gastroenterology, with early colorectal surgical involvement. Acute severe colitis should not be managed as routine outpatient diarrhoea.
💧 IV fluids: correct dehydration and electrolyte abnormalities, especially potassium and magnesium. Strict fluid balance and urine output monitoring are essential.
💊 IV corticosteroids: give IV hydrocortisone 100 mg QDS or equivalent. Assess clinical and biochemical response at 72 hours.
🛡️ VTE prophylaxis: give LMWH unless contraindicated because active IBD markedly increases thrombotic risk.
🦠 Treat co-existent infection: manage C. difficile, bacterial infection, CMV or sepsis according to microbiology advice.
⛔ Stop drugs that worsen colonic dilatation or bleeding risk: avoid loperamide, anticholinergics, opiates and NSAIDs where possible.
🍽️ Nutrition: assess nutritional status early. Use dietitian support; enteral nutrition is preferred if tolerated. Consider parenteral nutrition only if enteral intake is not possible or surgery is likely and nutritional status is poor.
🤝 MDT: daily gastroenterology review, early colorectal surgery input, IBD nurse involvement if available, and anaesthetic/ICU review if systemic compromise develops.

⚠️ Rescue Therapy - If Steroid-Refractory Around Day 3

🚨 Reassess at 72 hours: ongoing frequent bloody stools, persistent fever/tachycardia, rising CRP, falling albumin, worsening abdominal signs or systemic toxicity suggest steroid-refractory disease.
💊 Ciclosporin: NICE-supported rescue therapy for acute severe UC when IV corticosteroids fail. Typical specialist dosing is 2 mg/kg/day IV; monitor BP, renal function, magnesium, lipids and ciclosporin levels where used.
💉 Infliximab: option for acute exacerbations of severely active UC when ciclosporin is contraindicated or clinically inappropriate. Typical induction is 5 mg/kg IV, with further doses according to specialist IBD protocol.
🧬 Safety screening: TB/hepatitis screening should be performed before anti-TNF therapy where possible, but urgent rescue treatment should be discussed with specialists and not delayed unnecessarily in life-threatening disease.
🧪 Maintenance planning: after ciclosporin or infliximab, plan maintenance therapy with gastroenterology. Thiopurine-based maintenance may be appropriate after ciclosporin in selected patients, but this is not automatic.
🔪 Urgent colectomy: indicated for toxic megacolon, perforation, uncontrolled haemorrhage, severe systemic compromise, clinical deterioration despite medical therapy, or failure of rescue treatment. Do not delay surgery once criteria are met.

📏 Truelove & Witts Criteria

Parameter	Mild	Moderate	Severe
Bloody stools/day	<4	4–5	≥6
Temperature	Afebrile	Variable	>37.8°C
Heart rate	Normal	Variable	>90 bpm
Haemoglobin	>11 g/dL	10.5–11 g/dL	<10.5 g/dL
ESR	<20 mm/h	20–30 mm/h	>30 mm/h
CRP	Normal or mildly raised	Variable	>30 mg/L

🧪 Monitoring

💩 Daily stool chart: record stool frequency, blood, urgency and nocturnal symptoms.
📊 Daily bloods: FBC, U&E/creatinine, CRP, albumin and electrolytes; monitor magnesium and calcium if severe or on ciclosporin.
🫀 Vital signs: at least several times daily; more frequent observations if tachycardic, febrile, hypotensive or deteriorating.
💧 Fluid balance: strict input/output, daily weight if possible, monitor urine output and replace GI losses.
🩻 Imaging: abdominal X-ray if distension, severe pain, systemic toxicity or worsening clinical status; repeat imaging if concern for toxic megacolon.
🚨 Complications: actively check for toxic megacolon, perforation, sepsis, shock, VTE, AKI and electrolyte disturbance.

🚨 Toxic Megacolon / Surgical Red Flags

⚡ Toxic megacolon: colonic dilatation, typically transverse colon >6 cm, plus systemic toxicity such as fever, tachycardia, hypotension, dehydration or altered mental state.
🔪 Perforation: sudden severe abdominal pain, peritonism, shock, free air on imaging or rapidly rising inflammatory markers.
🩸 Massive haemorrhage: haemodynamic instability, falling haemoglobin or transfusion requirement.
🧫 Sepsis or multi-organ dysfunction: fever/hypothermia, hypotension, AKI, rising lactate or confusion.
📞 Action: urgent colorectal surgery, anaesthetics/ICU and gastroenterology review; do not persist with medical therapy if colectomy criteria are met.

💡 Exam / Clinical Tips 📝

🔹 Mnemonic for ASC severity: “6 BLOOD + SYSTEMIC” — ≥6 bloody stools/day plus fever, tachycardia, anaemia, ESR/CRP rise or other systemic toxicity.
🔹 Elderly and immunocompromised patients may show subtle signs: confusion, low-grade fever, anorexia, dehydration or mild diarrhoea.
🔹 Examine the abdomen gently: worsening tenderness, distension or peritonism should trigger urgent surgical review.
🔹 Pulse >90 bpm, postural hypotension, poor capillary refill or oliguria suggest hypovolaemia and systemic compromise.
🔹 Daily monitoring is not optional: stool chart + fluid balance + vitals + CRP trend detect deterioration early.
🔹 Falling albumin or rising CRP suggests severe inflammatory burden and poorer response to steroids.
🔹 Involve colorectal surgery early, not only when the patient is crashing; this improves decision-making if rescue therapy fails.
🔹 Colonic diameter >6 cm suggests toxic megacolon; free air suggests perforation.
🔹 Avoid full colonoscopy in acute severe colitis because insufflation and instrumentation increase perforation risk.

💡 Key Teaching Points

Acute severe UC is defined by ≥6 bloody stools/day plus systemic disturbance.
First-line inpatient treatment is IV corticosteroids, fluids, electrolyte correction, infection exclusion and VTE prophylaxis.
One-third may not respond to IV steroids, so day-3 reassessment is crucial.
NICE rescue wording: ciclosporin is the key rescue therapy; infliximab is an option when ciclosporin is contraindicated or clinically inappropriate.
Surgery saves lives when medical therapy fails or complications occur. Do not delay colectomy for toxic megacolon, perforation or worsening systemic toxicity.
Pathophysiology matters: mucosal inflammation causes diarrhoeal fluid loss, blood/protein loss and systemic inflammation, while colonic neuromuscular dysfunction can progress to toxic megacolon.

📚 References

```

The content on this website is provided for educational and informational purposes only to support exam preparation (e.g., MLA, MRCP, USMLE) and learning. This is NOT medical advice, diagnosis, treatment, or professional guidance. It does not replace consultation with a qualified healthcare professional, official guidelines (e.g., NICE, GMC, BNF), or supervised clinical practice. Always verify information with current, authoritative sources. Makindo and its contributors accept no liability for any reliance on this content, including errors, omissions, or any resulting harm, loss, or consequences. By using this site, you agree to these terms.