Onset & Duration: When did the colour change start? Persistent or intermittent?
Stool Characteristics: Colour, consistency (loose, hard, bulky), presence of blood/mucus.
Associated Symptoms: Abdominal pain, bloating, diarrhoea, constipation, jaundice, fatigue, weight loss.
Dietary Factors: Recent foods (beetroot, spinach, food dyes), iron supplements, travel history.
Medical History: Hepatobiliary disease, IBD, coeliac, pancreatitis, medications (antibiotics, antacids, iron).

🩺 Physical Examination

General: Look for jaundice, pallor, dehydration, cachexia.
Abdomen: Distension, tenderness, hepatosplenomegaly, abnormal bowel sounds.
Rectal Exam: Stool colour/consistency, check for blood.

🔬 Investigations

Stool Tests: FOBT, stool culture, faecal fat, calprotectin/lactoferrin.
Blood Tests: CBC, LFTs, amylase/lipase, renal profile, electrolytes.
Imaging: Abdominal US/CT, endoscopy/colonoscopy if bleeding suspected.

🎨 Stool Colour – Causes & Clinical Notes

⚫ Black (Melaena): - Upper GI bleed (ulcer, varices, gastritis) → black, tarry stool, anaemia, dizziness. - Non-pathological causes: iron, bismuth meds.
🔴 Red (Haematochezia): - Lower GI bleed (haemorrhoids, diverticulosis, colorectal cancer, IBD). - Bright red blood on tissue = likely anal fissure/haemorrhoids. - Urgent eval if persistent or with weight loss.
⚪ Pale/Clay-Coloured: - Biliary obstruction (gallstones, cholestasis, biliary atresia). - Hepatic disease (hepatitis, cirrhosis). - Often with jaundice, dark urine, pruritus.
💛 Yellow/Greasy (Steatorrhoea): - Fat malabsorption (coeliac, chronic pancreatitis). - Giardiasis or excess dietary fat. - Foul-smelling, floating stools with weight loss.
🟩 Green: - Rapid gut transit (gastroenteritis, IBS). - Green leafy vegetables, iron supplements, food dyes. - Usually benign if transient.
⚪ White/Chalky: - Barium after imaging. - Bile duct obstruction or severe hepatobiliary disease. - Needs correlation with jaundice and hepatology work-up.

🛠️ Management

Treat underlying cause: - Infections → antibiotics/antiparasitics. - GI bleed → PPI, endoscopy, surgery if severe. - Malabsorption → gluten-free diet (coeliac), enzyme replacement (pancreatitis). - Obstruction → surgical/endoscopic relief.
Medication Review: Adjust or stop contributing drugs (iron, antacids, antibiotics).
Dietary Advice: Explain benign food-related changes (beetroot, spinach, supplements).
Follow-Up: Monitor patients with chronic GI/hepatobiliary disease or unexplained persistent colour changes.

💡 Clinical Pearls

Persistent black or red stools → always exclude GI bleeding 🚨.
Pale stools + dark urine + jaundice → think obstructive jaundice.
Yellow greasy stools → suspect malabsorption (esp. coeliac, pancreatic insufficiency).
Green stools in children are often dietary or viral – usually benign.

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.

Change in stool colour

🧾 Clinical History

🩺 Physical Examination

🔬 Investigations

🎨 Stool Colour – Causes & Clinical Notes

🛠️ Management

💡 Clinical Pearls

Categories