Acute Diarrhea After Chemotherapy

💧 Chemotherapy Patient with Acute Diarrhoea – Internal Medicine Quiz

📜 HISTORY

🔹 60-year-old Male
🔹 Lung & Peritoneal Metastases (Unknown Primary Carcinoma)
🔹 Diagnosed 4 months ago
🔹 Receiving Platinum-based Combination Chemotherapy
🔹 Diarrhoea for 3 days
🔹 No fever

🩺 EXAMINATION

🔸 Afebrile
🔸 Pulse 98 bpm
🔸 BP 110/65 mmHg with likely postural drop
🔸 Clinically dehydrated
🔸 Left Iliac Fossa tenderness
🔸 No guarding or rigidity

🧪 INVESTIGATIONS

🔬 Hb 11.3 g/dL
🔬 WBC 6.5 ×10⁹/L
🔬 Neutrophils 5.4 ×10⁹/L (Not neutropenic)
🔬 Platelets 170 ×10⁹/L
🔬 CT Abdomen: Thickened Sigmoid Colon

❓ MCQ QUESTION

What is the most likely diagnosis?

A. Neutropenic Enterocolitis (Typhlitis)
B. Chemotherapy-Induced Colitis
C. Clostridium difficile Colitis
D. Peritoneal Metastases causing bowel inflammation

📝 Brief Case Summary

A 60-year-old man with metastatic cancer receiving platinum-based chemotherapy presents with acute diarrhoea, dehydration, left iliac fossa tenderness and CT evidence of sigmoid colonic thickening. Blood counts are normal and he is not neutropenic.

✅ Click to Reveal Answer

Answer: B. Chemotherapy-Induced Colitis

📚 Answer Explanation

Chemotherapy can directly injure rapidly dividing gastrointestinal mucosal cells, producing inflammation, ulceration and diarrhoea. The patient has recent chemotherapy exposure, normal neutrophil count, sigmoid colonic thickening and no evidence of severe infection, making chemotherapy-induced colitis the most likely diagnosis.

❌ Why Not Others?

A. Typhlitis
Usually occurs with severe neutropenia and commonly involves the caecum.

C. Clostridium difficile Colitis
Possible differential but no history of antibiotics, fever, leukocytosis or pseudomembranous features provided.

D. Peritoneal Metastases
Can cause obstruction or pain but less likely to cause acute diarrhoea with colonic wall thickening after chemotherapy.

🩺 Five Brief Case Scenarios

1. Neutropenic patient with RLQ pain → Typhlitis.
2. Chemotherapy + diarrhoea + normal counts → Chemotherapy colitis.
3. Recent antibiotics + profuse diarrhoea → C. difficile.
4. CMV infection in immunocompromised host → CMV colitis.
5. Ischemic bowel in elderly vascular patient → Ischemic colitis.

🧬 Pathophysiology Simplified

Chemotherapy damages intestinal epithelial cells → mucosal inflammation → impaired absorption → fluid secretion → diarrhoea → dehydration and electrolyte loss.

🔍 Physical Examination Pearls

• Assess hydration status.
• Check postural blood pressure.
• Look for abdominal tenderness.
• Evaluate for peritonitis.
• Examine for signs of sepsis.

🧪 Investigations – Choosing Wisely

• CBC with differential
• Electrolytes and renal function
• Stool culture if infection suspected
• C. difficile toxin assay
• CT abdomen when severe symptoms occur

⚠️ Complications

• Severe dehydration
• Acute kidney injury
• Electrolyte imbalance
• Sepsis
• Bowel perforation (rare)

💊 Management

• IV fluid resuscitation
• Correct electrolytes
• Hold offending chemotherapy temporarily
• Symptomatic antidiarrheal therapy when appropriate
• Exclude infectious causes
• Oncology review

📋 Differential Diagnosis

• Chemotherapy-induced colitis
• Clostridium difficile colitis
• Typhlitis
• Ischemic colitis
• CMV colitis
• Inflammatory bowel disease

🚨 Clinical Pitfalls

• Missing neutropenic enterocolitis
• Ignoring dehydration severity
• Delayed stool testing
• Overlooking electrolyte abnormalities
• Assuming all diarrhoea is infectious

💎 Clinical Pearls

• Normal neutrophil count argues against typhlitis.
• Chemotherapy commonly causes mucosal injury.
• Colonic wall thickening supports colitis.
• Dehydration often requires aggressive fluid replacement.
• Always exclude infectious causes.

🔄 Monitoring & Follow-up

• Fluid balance chart
• Daily weight
• Renal function monitoring
• Electrolytes
• Oncology reassessment before next chemotherapy cycle

❓ FAQ

1. What causes chemotherapy-induced colitis? — Mucosal injury from cytotoxic drugs.

2. Is it infectious? — Usually not, but infection must be excluded.

3. Why diarrhoea occurs? — Loss of mucosal integrity.

4. Is fever always present? — No.

5. Why assess neutrophil count? — To exclude typhlitis.

6. Which chemotherapy drugs commonly cause it? — Platinum agents, irinotecan, fluoropyrimidines.

7. Why perform CT scan? — Evaluate colitis severity and complications.

8. Can dehydration be severe? — Yes.

9. Is surgery usually needed? — Rarely.

10. Can recurrence occur? — Yes with subsequent chemotherapy cycles.

11. Why check stool tests? — Exclude infection.

12. Can AKI develop? — Yes from volume depletion.

13. What electrolyte disturbance is common? — Hypokalemia.

14. Can chemotherapy be restarted? — Often after recovery and oncology review.

15. What is the prognosis? — Usually good if recognized early.

📖 References

• ESMO Guidelines on Chemotherapy Toxicities
• ASCO Supportive Care Guidelines
• NCCN Management of Treatment-Related Toxicities
• Harrison's Principles of Internal Medicine
• Oxford Handbook of Oncology

🔑 Keywords

chemotherapy induced colitis,
chemotherapy diarrhea quiz,
colitis after chemotherapy,
oncology MCQ,
internal medicine quiz,
platinum chemotherapy toxicity,
sigmoid colitis CT findings,
cancer patient diarrhea,
typhlitis vs colitis,
medical education MCQ

📘 Follow Internal Medicine Quiz on Facebook

🔗 Explore More Topics:

🫀 Cardiology 🫁 Respiratory 🧠 Neurology 🩸 Hematology 🧪 Nephrology 🦠 Gastroenterology 🏥 Hepatology 🦴 Rheumatology 💉 Endocrinology 🩺 ABG 🧩 Psychiatry ☠️ Poisoning 🌿 Environment

🏠 Back to Home  |  📬 Contact Us  |  📋 About Us