Acute lower gastrointestinal haemorrhage secondary to colorectal malignancy can be difficult to manage, particularly when active bleeding is not demonstrated on imaging. Interventional radiology offers a minimally invasive option in selected cases, including empiric embolization.

CASE PRESENTATION
A 70-year-old patient with a known sigmoid colonic malignancy, currently undergoing neoadjuvant chemotherapy, presented with severe per rectal bleeding.
Contrast-enhanced CT demonstrated tumoural hyperenhancement but no definite contrast extravasation to suggest active bleeding. Despite conservative management, the haemorrhage persisted and became clinically significant.

INTERVENTION
Given ongoing bleeding and the absence of a demonstrable active source, a decision was made to proceed with empiric embolization.
Selective angiography of the inferior mesenteric artery was performed, and the superior rectal artery (terminal branch) was targeted. Percutaneous coil embolization was successfully undertaken (Figures 1–3).
Post-procedure, there was cessation of haemorrhage with no immediate complications.

OUTCOME
The intervention achieved effective haemostasis, stabilising the patient and allowing continuation of neoadjuvant therapy without interruption. No clinical evidence of bowel ischaemia was observed.

LEARNING POINTS
Absence of contrast extravasation does not exclude clinically significant bleeding in gastrointestinal haemorrhage.
Empiric (prophylactic) embolization is a valuable option when:
1. bleeding is ongoing or severe
2. localisation is suspected but not definitively demonstrated
3. risk of ischaemic complications is low
4. The superior rectal artery represents a favourable embolization target due to its collateral supply, reducing ischaemic risk.

ALTERNATIVE MANAGEMENT CONSIDERATIONS
1. Endoscopy: Limited utility in this case due to concern regarding luminal narrowing/stricture and risk of provoking further bleeding from a friable tumour.
2. Surgical resection: Deferred as it would have interrupted neoadjuvant chemotherapy, potentially impacting long-term oncological outcomes.

CONCLUSION
This case highlights the importance of clinical judgement in GI haemorrhage, demonstrating that empiric embolization can be both safe and effective in selected patients with tumour-related bleeding, even in the absence of radiologically proven active extravasation.