Lower GI Bleed

Gut, Liver & Pancreas · ICU Decoded chapter 56 · Locked — free with a referral

By Dr Javed Akhtar · Last reviewed 3 October 2026

Cited to ACG 2023 LGIB · ACG/SAR 2024 imaging · ASGE 2026.

Key points

Most are diverticular; 75% stop spontaneously; resuscitate + CT angiography if ongoing brisk bleed.
Positive CTA → catheter angiography with transcatheter arterial embolization; if CTA negative, proceed to prepared colonoscopy when stable; ongoing shock/brisk bleeding needs urgent GI/IR reassessment and further localization — tagged RBC scan mainly reserved for intermittent bleeding or when CTA unavailable.
Reverse anticoagulation for life-threatening bleeding; resume anticoagulation as early as clinically appropriate after hemostasis, based on thrombotic and rebleeding risk.
Small bowel sources: capsule or balloon enteroscopy after negative upper+lower studies.

Investigations

First tests: Full blood count, Blood group and crossmatch, Sodium, potassium, bicarbonate, urea and creatinine, PT/INR and aPTT.

Only if indicated: CT angiography for active GI bleeding, Colonoscopy, Upper GI endoscopy.

Repeat monitoring: Full blood count.

Management pathways in this chapter

Investigating Acute Lower Gastrointestinal Bleeding

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