Gastrointestinal bleeding

Gastrointestinal bleeding is a frequent presentation in emergency departments and a key cause for referral in Australian general practice.

1. Classification and Definitions

Dimension	Definition
Visibility	Overt: Visible bleeding (haematemesis, melena, haematochezia) Occult: FOBT/iFOBT+ or Iron Deficiency Anemia without visible bleeding Obscure: Ongoing/recurrent bleeding with negative high-quality OGD + colonoscopy
Anatomical Site	Upper GI: – Mouth to ligament of Treitz Mid-GI (small bowel): – Ampulla of Vater to terminal ileum Lower GI: – Caecum to rectum

2. Epidemiology

• Australia:
  • CRC remains a leading cause of LGIB despite screening.
  • High risk: elderly on NSAIDs + anticoagulants.
• Incidence/Mortality:

Type	Incidence (AU/Int.)	Mortality
Upper GI Bleed	50–150/100,000/year	6–8% (hospitalised)
Lower GI Bleed	~20–27/100,000 (int.)	4–10%
Small bowel/Obscure	~5–10% of GI bleeds	Risk: age, NSAIDs

3. Aetiology and Clinical Presentation

Upper GI Bleeding

Cause	Typical Symptoms	Comments
Peptic ulcer disease	Haematemesis melena epigastric pain	Often NSAID/aspirin-related H. pylori associated
Oesophageal/gastric varices	Large-volume haematemesis signs of chronic liver disease	Portal hypertension high mortality risk
Mallory-Weiss tear	Haematemesis after retching/vomiting	Sudden rise in intra-abdominal pressure
Erosive oesophagitis/gastritis	Coffee-ground vomitus reflux symptoms	Often in alcohol users NSAID users
Dieulafoy lesion (single abnormally large blood vessel (arteriole) beneath the gastrointestinal mucosa)	Massive, intermittent bleeding	Often missed requires high suspicion
Gastric/oesophageal carcinoma	Occult bleed, IDA weight loss dysphagia	Consider in patients >50 y or with alarm symptoms

Small Bowel Bleeding

Cause	Typical Symptoms	Comments
Angiodysplasia	Occult or overt painless bleeding	Elderly common in right colon and small bowel
Tumours (adenocarcinoma, GIST, NET)	Occult bleeding Iron Deficiency Anemia (IDA) abdominal mass or pain	GISTs may present with brisk bleeding
Meckel diverticulum	Painless haematochezia (younger patients)	Rule out with technetium scan in <40s
NSAID enteropathy	Occult bleeding ulceration	Often in chronic NSAID users elderly
Crohn disease	Bleeding with abdominal pain diarrhoea	Skip lesions terminal ileum most common site
Coeliac disease (ulcerative jejunoileitis)	Occult bleeding malabsorption Iron Deficiency Anemia(IDA)	Duodenal biopsies confirm more common in refractory cases

Lower GI Bleeding

Cause	Typical Symptoms	Comments
Diverticular haemorrhage	Sudden painless PR bleeding	Common in elderly often self-limiting
Angiodysplasia	Painless intermittent bleeding	Associated with – CKD – aortic stenosis
Colorectal cancer	Occult bleeding IDA change in bowel habit, weight loss	Right-sided cancers often present with anaemia only
Polyps	Occult bleeding or visible PR blood	May be sessile or pedunculated
Colitis (ischaemic, IBD, infectious)	Bloody diarrhoea with pain urgency	Assess with stool PCR imaging and scope
Haemorrhoids	Bright red PR bleeding especially after defecation	Diagnosis of exclusion external vs internal
Anal fissures	Painful PR bleeding with defecation	Often younger patients posterior midline
Aortoenteric fistula	Massive PR bleeding history of AAA repair	Surgical emergency consider in vascular surgery patients

4. Clinical Clues to Bleeding Source

Symptom/Sign	Likely Source	Clinical Insight
Haematemesis	Upper GI	Look for liver disease signs (varices) check BUN/Cr ratio
Coffee-ground vomitus	Upper GI (slow bleed)	Often erosive gastritis or duodenitis
Melena	>90% upper GI; may be small bowel or right colon	Black, tarry stool persistent odour
Maroon stool	Small bowel or proximal colon	Intermediate transit time often painless
Haematochezia	Left colon or brisk UGIB	Urgently exclude UGIB if unstable
Large-volume painless PR blood	Diverticular or angiodysplasia	Common in older adults often transient
Pain + bleeding	Ulcer, ischaemic or inflammatory colitis	Assess location/type of pain
Tenesmus + PR bleeding	Proctitis, rectal cancer	Often with urgency, mucus
Iron Deficiency Anemia + no visible bleeding	Occult GI bleeding	Consider – coeliac disease – NSAID use – malignancy
Intermittent melena + negative scopes	Small bowel source	Proceed to capsule/balloon endoscopy

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Occult (Chronic) GI Bleeding

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🔹 Epidemiology

• Occurs in context of:
  • Positive faecal occult blood test (FOBT)
  • Iron deficiency anaemia (IDA)
• In men and postmenopausal women, occult GI blood loss must be investigated, particularly to rule out malignancy (e.g. colorectal cancer)
• Prevalence (Australia)
  • iron deficiency affects ≈ 1.1 million people (≈ 20 % of women of reproductive age; 6 % of adult men).
  • High-risk cohorts – include Aboriginal & Torres Strait Islander adults, who have disproportionately higher rates of iron-deficiency anaemia (IDA).

🔹 Aetiology & Pathophysiology

➤ Sites

• Bleeding may arise anywhere from the oral cavity to the anorectum
• Upper GI source: 29–56% (most common)
• Colorectal source: 20–30%
• No source identified in 29–52%
• Small bowel source common in “obscure” GI bleeding (normal OGD/colonoscopy)

➤ Common Causes

• Mass Lesions:
  • CRC (especially right-sided)
  • gastric cancer
  • polyps
• Inflammatory:
  • IBD
  • severe esophagitis
  • peptic ulcers (NSAID/aspirin-related)
  • celiac disease
• Vascular:
  • Angiodysplasias (any site)
  • portal hypertensive gastropathy
• Infectious:
  • Hookworm in travellers/immigrants (still seen in northern Australia).
• Others:
  • Diverticula
  • Non-GI sources
    • Inherited bleeding disorders (von Willebrand)
    • (e.g. hemoptysis, epistaxis/oropharyngeal bleed)

🔹 Clinical Presentation

• Often asymptomatic, especially in early or elderly cases
• Symptoms of IDA: Fatigue, pallor, dizziness, pica, palpitations
• Clues on history:
  • Weight loss → malignancy
  • NSAID/aspirin use → ulcers
  • Anticoagulants/antiplatelets → bleeding risk
  • Family history → CRC or hereditary syndromes
  • Prior GI surgery
• Physical signs may indicate:
  • Celiac disease (dermatitis herpetiformis, glossitis)
  • IBD (extraintestinal signs)
  • Syndromic causes (Plummer-Vinson, Peutz-Jeghers)

🔹 Investigations

Colonoscopy + Upper endoscopy (OGD):

• Both recommended in IDA with positive FOBT
• Colonoscopy alone may be sufficient if no IDA and no upper GI symptoms

➤ If initial scopes are negative:

• Evaluate small bowel:
  • Capsule endoscopy (first-line)
  • CT or MR enterography (if mass/infiltrative suspected)
  • Deep enteroscopy (diagnostic + therapeutic)

Capsule Endoscopy

• Diagnostic yield: 55–92%
• Advantages:
  • Non-invasive
  • Visualises entire small bowel mucosa
• Limitations:
  • Not suitable for colonic lesions
  • Risk of capsule retention (esp. in strictures)
• Superior to push enteroscopy and barium studies

🔹Pathway:

Step 1 – Confirm IDA
• FBE + iron studies ± CRP.
• Check coeliac serology and urine dipstick.

Step 2 – Decide who scopes first

Group	First investigation	Target timeframe
Men & post-menopausal women	Colonoscopy and OGD	≤ 60 days
Premenopausal < 50 y, low risk	Treat iron deficiency; scope only if IDA persists or risk factors	—
Positive iFOBT (any sex)	Colonoscopy (OGD if IDA or UGI sx)	≤ 30 days

Step 3 – If scopes negative & IDA persists

1. Ensure adequate iron trial (≥ 6 w).
2. Capsule endoscopy (first-line).
3. Deep enteroscopy for biopsy/therapy.
4. CT or MR enterography if mural disease suspected.

Step 4 – Manage underlying cause & replenish iron (oral q2-3 d or IV per SA Health checklist).

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Investigations

When to Consider Gastroscopy

Clinical Scenario	Indication	Reasoning
Haematemesis or coffee-ground vomitus	Gastroscopy only	Suggests upper GI source (e.g. peptic ulcer, varices)
Melena (black, tarry stool), especially with normal PR exam	Gastroscopy first	Melena is more likely from upper GI tract
Dyspepsia with alarm symptoms (e.g. weight loss, IDA, dysphagia, age >50)	Gastroscopy only (initially)	Assess for malignancy, ulcers, Barrett’s oesophagus
Unexplained iron deficiency anaemia with prior normal colonoscopy	Gastroscopy only (± capsule if both negative)	May detect missed upper GI lesions (e.g. Cameron ulcers, coeliac)
Suspected coeliac disease (positive coeliac serology)	Gastroscopy with duodenal biopsies	Required for definitive diagnosis
Barrett’s oesophagus surveillance	Gastroscopy only	Routine surveillance based on risk stratification
Follow-up of known upper GI lesions (e.g. gastric ulcer, varices)	Gastroscopy only	For healing or banding surveillance

When to Consider Colonoscopy

Clinical Scenario	Indication	Reasoning
Fresh red PR bleeding (haematochezia), especially in patients >40	Colonoscopy first	Most likely lower GI source (e.g. diverticula, polyps, CRC)
FOBT-positive result (asymptomatic)	Colonoscopy only	Rule out colorectal malignancy or adenoma
Unexplained iron deficiency anaemia in older adult with normal OGD	Colonoscopy (if not done yet)	Right-sided colon cancer is common cause
Change in bowel habits, esp. with weight loss or anaemia	Colonoscopy	Evaluate for colorectal cancer
Surveillance of adenomatous polyps, IBD, or CRC history	Colonoscopy only	Routine screening or dysplasia surveillance
Persistent PR bleeding despite haemorrhoid diagnosis	Colonoscopy	Haemorrhoids are diagnosis of exclusion

When to Perform Both Gastroscopy AND Colonoscopy

Clinical Scenario	Rationale	Notes
Iron deficiency anaemia (IDA) without obvious source	Both OGD and colonoscopy needed	Common cause of occult GI bleeding; need to assess both ends
Melena with no source on OGD	Colonoscopy to exclude missed right-sided lesions	Up to 15% of melena may originate from right colon
Unexplained GI bleeding (occult or overt)	Full evaluation	If both scopes are normal → proceed to capsule/enteroscopy
Obscure GI bleeding (recurrent IDA or overt bleeding with normal scopes)	Both already done → next: capsule endoscopy	Obscure bleeding usually small bowel in origin
Age >50 with multiple GI symptoms (e.g. PR bleeding + dyspepsia + IDA)	Full upper and lower evaluation	Consider malignancy in multiple segments
iFOBT-positive + dyspepsia + risk factors (e.g. smoking, alcohol, weight loss)	Consider both	Dual pathology is not uncommon in older patients

Decision-Making Pearls

Clinical Clue	Suggests	Scope First?
Haematemesis, melena	Upper GI source	Gastroscopy
Fresh PR bleeding, change in bowel habit	Lower GI source	Colonoscopy
IDA, positive FOBT, weight loss	Could be either	Both (OGD + colonoscopy)
Normal colonoscopy in IDA	Upper GI missed cause	Gastroscopy or capsule
Normal scopes, ongoing bleeding	Small bowel source	Capsule → balloon enteroscopy

QH Endoscopy Clinical Prioritisation Criteria Triage

Investigation	Category 1 (≤30 days) 🔴 Urgent	Category 2 (≤90 days) 🟠 Semi-urgent	Category 3 (≤365 days) 🟢 Routine
Gastroscopy	– Haematemesis – Melena – Dyspepsia with alarm features:  • Age >50 with new symptoms  • Weight loss ≥5%  • Persistent vomiting  • Dysphagia or odynophagia  • IDA	– Refractory dyspepsia (not responding to ≥8 weeks PPI, no alarm features)	– Surveillance: • Barrett’s_Oesophagus • Coeliac Ds followup • Post-variceal banding
Colonoscopy	– Positive iFOBT +:  • Rectal bleeding  • IDA  • Mass on exam or imaging	– Non-alarming PR bleeding (e.g. bright red blood without anaemia or other alarm features)	– CRC screening: •Moderate FHx ofCRC •Asymptomaticpatients •Past_polyps_surveillance
Both scopes	– Unexplained IDA – Occult GI bleeding (positive iFOBT, negative previous scopes)	N/A	N/A

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https://australianprescriber.tg.org.au/articles/management-of-acute-bleeding-in-the-upper-gastrointestinal-tract.html

ACUTE UPPER GI BLEEDING

A. Clinical History

• Bleeding features:
  • Haematemesis: bright red vomitus (varices or ulcer)
  • Coffee-ground emesis: slower upper GI bleeding (gastritis, oesophagitis)
  • Melena: black tarry stools → usually from upper GI
  • Haematochezia: may indicate brisk upper GI bleeding
• Associated symptoms:
  • Dizziness, presyncope, syncope → volume loss
  • Epigastric/RUQ pain → peptic ulcer, gastric pathology
  • Dyspepsia/reflux → non-variceal cause
  • Weight loss, anorexia → malignancy
  • Fever/chills → infectious cause
• Medication and risk history:
  • NSAIDs, aspirin, antiplatelets, SSRIs
  • Anticoagulants (warfarin, DOACs)
  • Alcohol history → varices
  • History of CLD, liver transplant, variceal bleed

B. Physical Examination

Component	Key Findings	Interpretation
Vitals	Hypotension, tachycardia, postural drop	Shock or active bleeding
General inspection	Pallor, diaphoresis, agitation, confusion	Anaemia, hypoperfusion
Abdomen	Epigastric tenderness, hepatosplenomegaly	Ulcer or portal hypertension
PR exam	Melena, blood, or clots	Confirms GI source
Stigmata of CLD	Spider naevi, ascites, asterixis	Suggests variceal source

C. Investigations

• Initial bloods:
  • FBC (Hb drop), UEC (↑urea from digested blood), LFTs
  • INR/APTT: coagulopathy
  • Group and hold / cross-match (2–6 units if severe)
  • CRP, lipase (if pancreatitis suspected)
• Risk stratification:
  • Glasgow-Blatchford Score: for early discharge decisions
  • Rockall Score (pre- & post-endoscopy): mortality/rebleed risk

🔹 Risk Stratification Tools

1. Glasgow-Blatchford Score (Pre-endoscopy)

• If:
  • Urea <6.5 mmol/L
  • Hb >130 g/L (M) or >120 g/L (F)
  • SBP >110 mmHg
  • HR <100 bpm
    → Consider outpatient management (if no syncope/other concerns)

2. Rockall Score (Pre + Post-Endoscopy)

Factor	Score 0–3
Age	<60 to ≥80
Shock	No → Hypotension
Comorbidity	None → Liver/Renal/Malignancy
Endoscopic Dx	Mallory-Weiss → GI malignancy
Endoscopic signs	None → Spurting vessel/clot

• Score ≤2: low risk (4% rebleed, 0.1% mortality)
• Score ≥8: 50% chance of rebleed

D. Management

• Resuscitation:
  • 2 x large-bore IV cannulas (16G)
  • IV crystalloids → target SBP >100 mmHg
  • Transfuse: PRBCs if Hb <70 g/L (<90 if CVD)
  • Reverse anticoagulation (vitamin K, PCC, platelets)
• Pre-endoscopy therapy:
  • IV PPI: pantoprazole 80 mg bolus → 8 mg/hr infusion
  • Suspected varices: octreotide infusion + ceftriaxone 1 g IV
• Endoscopy (OGD):
  • Within 6–12 hrs if unstable
  • Within 24 hrs if stable
  • Therapeutic options: adrenaline injection, thermal coagulation, clips, banding
• Secondary prevention:
  • PPI long-term if ulcer
  • Eradicate H. pylori if positive
  • Cease NSAIDs; if essential, add PPI
  • For varices: non-selective β-blocker + regular banding
  • Alcohol cessation, nutritional support

Preventing Recurrent Bleeding

Non-Variceal

NSAID-associated ulcers

• Discontinue NSAID if possible.
• Heal with PPI > H2 antagonist × 6 weeks.
• Gastric ulcer: repeat endoscopy in 8 weeks.
• If NSAID required:
  • Use PPI + NSAID or COX-2 inhibitor ± PPI
  • Avoid aspirin if possible; if essential, co-prescribe PPI.

H. pylori-associated ulcers

• Test and eradicate H. pylori (e.g. triple therapy × 7 days).
• Confirm eradication and healing → no ongoing therapy required.

Idiopathic ulcers

• PPI or H2 antagonist × 6–8 weeks.
• May need long-term acid suppression.

Variceal Bleeding

• Recurrence in 2/3 patients.
• Endoscopic banding (preferred) or sclerotherapy, repeated every 1–3 weeks.
• Add non-selective β-blocker (e.g. propranolol ± nitrate).
• TIPS or surgery if recurrent/uncontrolled.
• Alcohol abstinence critical in alcoholic liver disease.

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ACUTE LOWER GI BLEEDING

A. Clinical History

• Bleeding characteristics:
  • Bright red blood per rectum (BRBPR): likely distal source (e.g. haemorrhoids, rectal cancer)
  • Blood mixed with stool: left-sided colon
  • Maroon stool: right colon or small bowel
  • Melena: may be proximal or misclassified UGIB
• Associated features:
  • Pain → suggests colitis, ischaemia, IBD
  • Weight loss, anaemia symptoms → malignancy
  • Tenesmus → rectal cancer or proctitis
  • Fever → infectious or inflammatory
• Medication history:
  • Anticoagulants/DOACs
  • NSAIDs, aspirin
• Past history:
  • Prior polyps, CRC, IBD, radiotherapy, colonoscopy findings
  • FHx of CRC or hereditary polyposis syndromes

B. Physical Examination

Component	Key Findings	Interpretation
Vitals	Tachycardia, hypotension	Active bleeding
General	Pallor, fatigue	Anaemia, volume depletion
Abdominal exam	Tenderness, palpable mass, distension	Inflammatory vs malignancy
PR exam	Fresh blood, melena, masses, haemorrhoids	Confirms source and helps triage
Perianal exam	Haemorrhoids, fissures	Localised anorectal source

C. Investigations

• Blood tests:
  • FBC (microcytic anaemia), CRP (inflammation), iron studies
  • Coagulation screen, renal function
• Imaging:
  • CT abdomen/pelvis with contrast → if mass, abscess, or ischaemia suspected
  • Abdo US in younger patients or if gynaecologic pathology considered
• Stool studies (if diarrhoea):
  • Faecal calprotectin, PCR panel (C. difficile, Campylobacter, etc.)
• Endoscopy:
  • Urgent colonoscopy within 24 hrs if unstable
  • Elective colonoscopy if stable + red flags
  • Consider flexible sigmoidoscopy in young low-risk with minor bleed

D. Prevention and Secondary Care

• Definitive treatment:
  • Polypectomy, IBD control, haemorrhoid banding/sclerotherapy
• Medication review:
  • Rationalise NSAIDs, dual antiplatelets, anticoagulants
  • If antiplatelet essential → consider PPI
• Cancer prevention:
  • Enrol in NBCSP (iFOBT every 2 yrs, ages 50–74)
  • Follow NHMRC and RACGP Red Book screening intervals
• Surveillance colonoscopy:
  • Personal hx: adenomas, CRC, IBD → per GESA intervals
  • Family hx of CRC: stratify based on risk
• Lifestyle:
  • Optimise dietary fibre and hydration
  • Avoid smoking, excess alcohol
  • Encourage regular bowel habit and physical activity