21. Rectal Bleeding

Question 1

How can the differential diagnosis of rectal bleeding be categorised?

Answer 1

They can be categorised based on the source of the bleed
Anorectal
Colonic 
Ileojejunal
Upper GI

Question 2

List some differentials for rectal bleeding from the anorectal region

Answer 2

Haemorrhoids 
Anal fissure 
Rectal tumour 
Anal tumour 
Anal fistula

Question 3

List some differentials for rectal bleeding from the colonic region

Answer 3

Diverticular disease 
Angiodysplasia
Colitis (inflammatory, ischaemic, infective) 
Colonic tumour (benign or malignant)
Iatrogenic

Question 4

List some differentials for rectal bleeding from the ileojejunal region

Answer 4

Coeliac disease 
Aorto-enteric fistula 
Small bowel tumours
Peptic ulceration (Meckel’s diverticulum)
Angiodysplasia

Question 5

List some differentials for rectal bleeding from the Upper GI region

Answer 5

Peptic ulcer 
Oesophageal varices 
Mallory-Weiss tear 
Aorto-enteric fistula 
Osler-Weber-Rendu syndrome 
Dieulafoy lesion

Question 6

List some important questions to ask about the history of presenting complaint.

Answer 6

How much blood has passed?
How long have you had rectal bleeding and how often do you experience it?
What does the blood look like?
Describe the relationship between the blood and the stools.
Is there any pain or prolapse when opening your bowels?
Has there been a feeling of incomplete emptying of your bowels after you’ve gone to the toilet (tenesmus)?
Has there been a change in bowel habit?
Have you lose weight?
Ask about signs of anaemia (e.g. lethargy, breathlessness)

Question 7

Describe the different appearances of blood in stools.

Answer 7

Frank blood = haematochezia

Black, tarry stools = melaena

Question 8

Other than melaena, what else can cause black tarry stools?

Answer 8

Iron supplements

Question 9

Explain how the relationship between the blood and the stool can give clues about the source of the bleed.

Answer 9

Blood mixed with stool – lesion is proximal to the sigmoid colon, so it can mix with loose stools
Blood streaked on stool – sigmoid or anorectal source
Blood separate from stool – haemorrhoids can cause bleeding after defecation. Some bleeding may be sufficient to trigger defecation (e.g. diverticular bleeds, angiodysplasia, IBD)
Blood is only on toilet paper – suggest minor bleeding from anal canal (e.g. haemorrhoids, anal fissure)

Question 10

Most causes of rectal bleeding are painless. Which cause of rectal bleeding is known for causing intense pain?

Answer 10

Anal fissures cause an intense tearing pain on defecation

Question 11

What does tenesmus suggest?

Answer 11

It suggests that there is a space-occupying lesion in the rectum

Question 12

What can cause bloody diarrhoea?

Answer 12

Ischaemic colitis

Ulcerative colitis

Question 13

What can cause bloody, mucoid diarrhoea?

Answer 13

Proctitis
Rectal cancer
Villous adenomas

Question 14

Chronic GI blood loss can lead to anaemia. Which symptoms of anaemia should you ask the patient about?

Answer 14

Breathlessness

Fatigue

Question 15

List some key features of the past medical history that you should ask about.

Answer 15

Previous rectal bleeding
Ulcerative colitis
Recent bowel trauma (e.g. surgery, colonoscopy)
Aortic surgery
Radiotherapy to the rectum
Bleeding tendency
PMH of risk factors for upper GI bleeds (e.g. peptic ulcer disease, chronic liver disease)

Question 16

Which types of drugs are particularly important to take note of in a patient with rectal bleeding?

Answer 16

Increased bleeding tendency (e.g. anticoagulants, antiplatelets)
Increased risk of peptic ulcers (e.g. NSAIDs, steroids, bisphosphonates)
Increased risk of C. difficile colitis (e.g. antibiotics, PPIs)
Drugs that attenuate the cardiac response to hypovolaemia (e.g. beta-blockers)

Question 17

Why is it important to check for Virchow’s lymphadenopathy in a patient presenting with rectal bleeding?

Answer 17

It is a sign of GI malignancy

Question 18

Before performing a DRE, what do you inspect the anus for?

Answer 18

Skin tags
Anal fissures
Haemorrhoids
Anal fistulae

Question 19

Under what conditions will haemorrhoids be palpable on DRE?

Answer 19

If the haemorrhoid is prolapsed or thrombosed

Question 20

List some important blood tests to conduct in a patient with rectal bleeding. Explain why these tests are important.

Answer 20

FBC – chronic GI bleeding can lead to anaemia
Clotting screen – check if the patient has a bleeding tendency
Urea – high urea is consistent with upper GI bleeds (due to digestion of red blood cells)

Question 21

Which methods of visualising the anus, rectum and sigmoid colon can be performed at the bedside of a patient with rectal bleeding?

Answer 21

Proctoscopy

Rigid sigmoidoscopy

Question 22

List some imaging methods used to identify the source of the bleeding.

Answer 22

Colonoscopy
Mesenteric angiography
CT angiography
Technetium-99 m-labelled red blood cell scintigraphy
Upper GI endoscopy
Small bowel visualization by enteroscopy or video capsule endoscopy

Question 23

Which cause of rectal bleeding is mesenteric angiography particularly useful for diagnosing and treating?

Answer 23

Angiodysplasia

Question 24

List two causes of upper GI bleeding that are difficult to visualise.

Answer 24

Angiodysplasia

Dieulafoy lesion

Question 25

Define angiodysplasia.

Answer 25

An abnormal collection of small blood vessels usually in the lining of the GI tract, which can bleed
They are common in the large and small intestine but can also be found in the lining of the stomach and mouth

Question 26

List the treatment options for angiodysplasia.

Answer 26

Embolisation
Surgical resection
Endoscopic laser electrocoagulation

Question 27

List the treatment options for haemorrhoids under conservative, medical and surgical methods

Answer 27

Conservative

• Increase dietary fibre
• Improve hydration
• Avoid straining at the stool

Medical

• Local anaesthetics
• Steroidal creams
• Laxatives

Surgical

• Rubber band ligation
• Injection sclerotherapy
• Haemorrhoidectomy
• Stapled haemorrhoidopexy

Question 28

Which class of drugs increases the risk of diverticular bleeds?

Answer 28

NSAIDs

Question 29

Which scoring system is used to predict the risk of future diverticular bleeds?

Answer 29

HAS-BLED

Question 30

Describe two surgical procedures that are used for patients with diverticular disease.

Answer 30

Hartmann’s procedure – proctosigmoidectomy with an end colostomy and a rectal stump
Primary anastomosis – resection of the affected portion of bowel with anastomosis of the loose ends – a loop ileostomy may be used to allow the primary anastomosis to heal

Question 31

Most anal fissures heal spontaneously. Why do deep fissures heal more slowly?

Answer 31

Anal sphincter spasm restricts the anal blood supply, which is required for healing

Question 32

What are the main aims of treatment of anal fissures?

Answer 32

Reduce anal sphincter spasm
Reduce tearing of the anal mucosa
Promote healing

Question 33

Describe the medical treatment options for anal fissures.

Answer 33

High-fibre diet with laxatives
Avoid constipating analgesics (e.g. opioids)
Topical anaesthetics (e.g. lidocaine)
Topical GTN (relaxes the anal sphincter and promotes healing)
Topical diltiazem
Botox injections

Question 34

Describe the surgical treatment options for anal fissures.

Answer 34

Lateral internal sphincterectomy (this comes with a risk of faecal incontinence)
Anal advancement flap