Lecture on lower GI bleed for medical students. Encompasses pathophysiology, classification, principles and tips on management.

1. Lower GI bleed
Chea Chan Hooi
Surgeon
Sibu Hospital

2. Content
• Introduction
• Definition
• Classification
• Clinical features
• Principles of management
• Special discussion – Diverticular bleed

3. Introduction
• 20 – 33% of GI bleed cases
• Wide spectrum of presentation
• Potentially life-threatening

4. Definition
• Bleeding within GI tract distal to ligament of
Trietz

5. Classification by etiology
• Infective amoebic, typhoid, dysentery, TB
• Neoplasm polyps, tumour
• Degenerative diverticulosis, angiodysplasia
• Inflammatory IBD
• Autoimmune SLE
• Trauma blunt, penetrating
• Iatrogenic radiation, scope ± intervention
• Vascular AVM, haemangioma, ischaemia

6. By severity

7. Clinical features
• Haematochezia
• Melaena
• Fresh rectal bleed
• Anaemic symptoms
• Localising symptoms
• Red flags
• Coagulation disorders, antiplatelets

9. Principles of management
• Resuscitation
– IVF challenge
– Blood product transfusion
– Majority stop spontaneously
• Identify cause of bleed + haemostasis
• Definitive treatment

10. Investigations
• Endoscopy
– Anoscopy
– Proctoscopy
– Sigmoidoscopy
– Colonoscopy
• Initial diagnostic method of choice
• IDs cause up to 90%
– Enteroscopy
– Capsule endoscopy

11. • Imaging
– Angiography
• Bleed rate ≥1.0ml/min
• Pros : therapeutic in same setting
• Cons : invasive, high dose radiation
– CT angiography of mesentery
• Bleed rate ≥0.5ml/min
• Pros : anatomically detailed, relatively easily available
• Cons : non-therapeutic
– RBC-tagged scintigraphy
• Bleed rate ≥0.1ml/min
• Pros : detect minute amount of bleeding
• Cons : poor anatomical correlation, time consuming, now widely
available

13. Enteroscopy
• Push enteroscopy
– An extra-long upper endoscope with an average reach of
proximal 70cm of small bowel
• Balloon –assisted enteroscopy
– Single & double balloon
– Inflatable balloons to grip the intestine to facilitate deep
enteroscopy
– Largest body of evidence on enteroscopy is based on
double-balloon enteroscopy
• Spiral enteroscopy
– A specialised overtube with a compliant spiral located at
the distal tip

19. Definitive treatment
• Depends on etiology, severity of bleed, patient’s
haemodynamic & premorbid status
• Options
– Medical
– Intervention radiology
– Surgery
• Discuss common etiologies
– Tumour
– Angiodysplasia
– Diverticular
– Haemorrhoids

20. Diverticular bleed

21. Introduction
• Most common cause of LGIB
• Bleeding complicates 5 – 15% of patients with
diverticulosis
• 80% will cease spontaneously
• 30 – 40% will have recurrent bleed
• Bleeding tends to complicate right sided
diverticuli

22. Pathogenesis of colonic diverticular
bleed
• At sites of weaknesses in the colonic wall –
where vasa recta penetrates
• Mucosa herniates thru  pseudodiverticulum
• Vasa recta draped over the dome of the
diverticulum  susceptible to trauma and
disruption
• Intimal damages  eccentric thickening 
wall weakening  rupture

23. Other contributory factors
• Atherosclerosis
• NSAIDs
• Hyperuricaemia  oxidised LDL  oxygen
free radicals
• Faecoliths

26. Principles of management
• Resuscitation
• Endoscopy for localisation & haemostasis
• Angioembolisation
• Surgery

30. TA!
Q&A?