UrgentEmergency Guide
Blood in stool: Red Flags & Emergency Signs
Rectal bleeding should never be attributed to haemorrhoids without excluding colorectal cancer, especially in anyone over 50 or with change in bowel habit.
🚨 Call 999 / 112 Immediately
- ⚠Massive rectal bleeding with haemodynamic instability — lower GI haemorrhage, call 999
- ⚠Dark tarry stool (melaena) — upper GI bleed (peptic ulcer, varices)
- ⚠Rectal bleeding with extreme pallor, dizziness, and tachycardia — significant haemorrhage
⚡ See a Doctor Today
- •Rectal bleeding in anyone over 50 — 2-week wait colonoscopy
- •Blood mixed with stool (not just on paper) with change in bowel habit — colorectal cancer
- •Rectal bleeding with abdominal pain and weight loss — IBD or malignancy
High-Risk Combinations
When blood in stool occurs together with any of these symptoms, urgency increases significantly:
Conditions to Rule Out Urgently
Colorectal Cancerurgent
FIT test + colonoscopy; CT staging; 2-week wait referral
Upper GI Haemorrhage (Melaena)emergency
Endoscopy within 24 hours; PPI infusion; blood transfusion
Ischaemic Colitisurgent
CT abdomen + colonoscopy; surgical review
Condition Authority Pages
Differential diagnosis analyses:
When to Call Emergency Services
- →Large rectal bleed with dizziness, pallor, or collapse
- →Black tarry stools with lightheadedness