GI - Lower GI bleed

Question 1

Lower GIB

Anatomical definition
Possible sections of GIT involved

Answer 1

Definition: bleeding from gut distal to ligament of Treitz

Small bowel, colon, rectum and anus

Question 2

Causes of anorectal bleed

Answer 2

Anorectal (~10%):

1. Haemorrhoids
2. Fissure-in-ano
3. Anal or rectal ulcers
4. Rectal varices
5. Proctocolitis: IBD, radiation, infection

Question 3

Causes of large bowel bleed

Answer 3

Diverticular disease* (17-40%)
Angiodysplasia* (2-30%)
Colitis (9-11%):

• Infective: C. dificile, CMV, amoebic, TB
• Inflammatory: ulcerative colitis, Crohn’s disease
• Ischaemic colitis
• Radiation

Neoplasm (7-33%): carcinoma, large polyps, post-polypectomy

Question 4

Features of LGIB that suggests outlet bleeding

Answer 4

• Fresh blood
• Separated from stool
• Variable, usu. small amount
• Anorectal symptoms
• No haemodynamic disturbance

Question 5

Diverticular bleeding

• Prevalence
• Cause
• GIT site
• S/S
• Dx
• Mx

Answer 5

• Prevalence = Most common
• Cause = Outpouching of intestinal wall through blood vessel penetration defects >> Rupture of Vasa recta into diverticulum
• GIT site = more commonly on the right
• S/S = self-limiting, painless hematochezia, but recur frequently
• Dx = endoscopy, angiography
• Mx = resuscitation, endoscopic therapy, semi-elective resection after 2nd bleeding episode

Question 6

List 3 vascular causes of LGIB

Answer 6

Angiodysplasia

Hemorrhoids

Rectal varices

Question 7

GIT angiodysplasia

• Definition
• Cause
• Demographic
• Site in GIT
• Associated diseases

Answer 7

• Definition = dilated, tortuous submucosal vessels
• Cause = usually degenerative condition
• Demographic = occur in elderly (2/3 at >70y) but is uncommon
• Site in GIT = commonly on Rt colon/caecum
• Associated vascular diseases = Osler-Weber-Rendu disease, aortic stenosis (Heyde syndrome)

Question 8

GIT angiodysplasia

S/S

Dx

Mx

Answer 8

S/S:

• INTERMITTENT BLEED
• painless haematochezia of variable severity, mostly self-limiting (85-90%)
• can be overt (tends to bleed less than diverticular disease as it is venous bleeding)
• rebleed in 25-85%

Dx: endoscopy, (angiography)

Mx: endoscopic therapy, (angiography)

Question 9

Hemorrhoids

Definition

Risk factors

S/S

Dx

Mx

Answer 9

Due to dilated vascular cushions of anal canal (haemorrhoidal plexus)
Very common! – 4.4% in general population
RFs: chronic straining, obesity/prolonged sitting

S/S:

• typically painless haematochezia that is related to defecation (typically coats stool or stains tissue paper),
• may be a/w anorectal S/S, eg. mucus discharge, sense of prolapse, anal itchiness, pain

Dx: proctoscopy
Mx: banding, haemorrhoidectomy

Question 10

Rectal varices

Cause

S/S

Mx

Answer 10

Due to portal hypertension (portosystemic shunt between superior and inferior rectal vv.)

S/S: often presents with severe bleeding
Mx: injection sclerotherapy (local), TIPS/ Shunting (if uncontrolled bleeding)

Question 11

Radiation proctocolitis

Cause

Pathogenesis

Time to onset of S/S

S/S

Answer 11

Cause: RT for pelvic malignancies

Pathogenesis:

• epithelial atrophy and fibrosis associated with obliterative endarteritis >> chronic mucosal ischaemia
• Formation of vascular telengiectasia

Timing: can be acute (<6w) or delayed (>9mo but can be >10y)

S/S: diarrhoea, rectal uregency/tenesmus, bleeding

Question 12

Radiation proctocolitis

Dx

Mx

Answer 12

Dx: to r/o other causes of proctocolitis + endoscopy with Bx

Mx:

• *- Topical: sucralfate or glucocorticoid enema**
• *- Endoscopic: argon plasma, Infra-red coagulation, laser, 4% formalin injection**

Surgery: unstoppable bleeding

-Diversion or Proctectomy (deadly, not done)

Question 13

IBD

• Pathogenesis
• 2 major clinical entities
• Different sections of bowel involved

Answer 13

Pathogenesis: Defects in epithelial cell junctions > bacterial components infiltrate gut mucosa > Chronic inflammatory disorder of small and/or large intestine, hyperactive mucosal immune response

Crohn’s disease and Ulcerative colitis

Question 14

Colorectal cancer LGIB

Cause

S/S

Mx

Answer 14

result of overlying erosion or ulceration

S/S:

• low-grade, intermittent bleeding (may presents with iron-deficiency anaemia or FOBT+),
• may be a/w changes in bowel habit (alternating diarrhoea and constipation, penciling of stool, tenesmus)

Mx: endoscopic Tx has limited role

Question 15

Outline 11 key questions in history taking for LGIB

Answer 15

Bleeding history:

• Presentation: acute or chronic, occult or overt?
• How was blood found? Mixed with stools, on stool, on toilet paper, after defecation, overt?
• Severity of bleeding: mild or heavy?
• Color of blood?
• Previous history of bleeding episodes?

GI symptoms:

• Bowel output? – frequency, consistency, colour, anorectal symptoms
• UGIB signs? Pain?

Malignancy screening: risk factors, bowel habits, constitutional symptoms, metastatic symptoms?

Complications?

• Shock: extreme thirst, confusion, pallor, oliguria
• Symptomatic anaemia: SOB on exertion, postural dizziness, syncope, chest pain, palpitation, lethargy or fatigue

PMH?

• Previous bleeding +/- Investigations, significant co-morbid conditions?

Drugs?

→ NSAIDs: can give rise to small bowel ulcers
→ Antiplatelets, anticoagulants

Question 16

Differentiate likely GIT location of LGIB based on following presentations

→ Blood mixed with faeces
→ Blood on surface of stool
→ Blood on toilet paper
→ Blood after defecation
→ Blood by itself: torrential bleeding

Answer 16

→ Blood mixed with faeces: from above sigmoid
→ Blood on surface of stools: from anus/rectum
→ Blood on toilet paper: usually mild bleeding from sources close to anal margin
→ Blood after defecation: from anus, eg. haemorrhoids
→ Blood by itself: torrential bleeding, eg. diverticular disease, angiodysplasia

Question 17

List common causes of mild LGIB mixed with stools

List common causes of heavy LGIB (overt)

Answer 17

mild LGIB: anorectal pathologies, carcinoma, colitis

Heavy, overt LGIB : diverticular disease, angiodysplasia, Meckel’s diverticulum, ischaemic colitis, rectal varices

Question 18

Red flag S/S of LGIB suggestive of malignancy

Answer 18

□ Risk factors: >50y, male, smoker, FHx, Hx of IBD, polyps and colorectal CA

□ Bowel habits: alternating constipation and diarrhoea, pencil thin stools, tenesmus

□ Constitutional symptoms: loss of appetite, loss of weight, malaise

□ S/S of spread: intractable pain (sacral n. invasion), irritative urinary symptoms (bladder), ascites (peritoneal), jaundice/RUQ discomfort (liver), bone pain (bone), SOB (lungs)

Question 19

First-line management/ resuscitation of LGIB

Answer 19

Resuscitation and stabilization of haemodynamics

ABC:
□ A: intubate if decompensated (confused) or massive haematemesis
□ B: O2 cannula
□ C: large bore IV cannula with crystalloid infusion ± blood transfusion

Monitor haemodynamic status by:
□ Shock chart hourly
□ Vitals: BP/P, RR, body temp
□ Foley’s catheter: urine output ≥0.5mL/kg/h
□ Cardiac monitor, pulse oximetry
□ ± CVP line for PAWP

First-line blood:
□ CBC: Hb, haematocrit
□ RFT: hydration status, pre-renal failure, electrolyte imbalance
□ LFT, clotting profile: coagulopathy
□ T/S for transfusion

Question 20

Indications for blood transfusion for LGIB

Answer 20

Transfuse if
□ Profuse bleeding
□ Persistent haemodynamic instability despite crystalloid resuscitation
□ Symptomatic anaemia
□ Acute MI/unstable angina with low Hb

Question 21

Modalities to localize LGIB (6 + additional subtypes)

(except small bowel bleeds)

Answer 21

1. Proctoscopy, sigmoidoscopy (exclude anorectal bleed)
2. NG tube: bile-stained aspiration excludes UGIB
3. Endoscopy: OGD first-line**

→ Colonoscopy for lower GI bleeding
→ Enteroscopy for small bowel bleeding
→ Upper endoscopy to exclude upper GI bleeding
→ Intraoperative endoscopy during laparotomy to assess both intra- and extraluminal pathologies

4. CT Angiography
5. Radionuclude scans: RBC scan, sulphur colloid scan
6. Other imaging: CT scan, small bowel enteroscopy

Question 22

Why should OGD be performed before colonoscopy for LGIB

Answer 22

(1) PUD management is easier than LGIB
(2) ‘E’ colonoscopy without bowel prep is not ideal
(3) If the source is from upper GI, then ‘E’ colonoscopy cannot see anything because it will be full of blood

Question 23

Colonoscopy for LGIB

• Function
• Bowel preparation required or not?
• Advantages
• Therapeutic modalities

Answer 23

Function:

• localize bleeding, performed early to obtain a diagnosis before bleeding stops
• intubate the ileocaecal valve to exclude distal SB bleeding

Bowel preparation: preferred if possible

• Increase diagnostic yield without increase morbidity
• NOT feasible in unstable patients

Advantages:

• Low complication rate
• Shorter hospital stay
• Diagnostic yield 75-90%

Therapeutic modalities:

• Sclerosant/vasoconstrictor injections, heat probe, electrocoagulation, laser, haemoclips, argon beam coagulation

Question 24

Modalities to localize occult LGIB

Answer 24

Repeat upper endoscopy or colonoscopy

Look for small bowel bleed:
→ Enteroscopy/ video capsule enteroscopy
→ Angiography
→ RBC scan: non-specific
→ Contrast CT scan
→ Small bowel enema

Question 25

Indications for surgery for LGIB

Answer 25

Indications:
→ Haemodynamic instability despite adequate resuscitation
→ Massive blood transfusion (>6 units)
→ Frequent re-bleeding
→ On anticoagulant or antiplatelets

Question 26

Surgical treatment options for LGIB

Rebleeding rate for each option

Answer 26

With localization: segment resection

Without localization

• Subtotal/total colectomy if bleeding from colon
• Intraoperative colonoscopy or enteroscopy for localization

Segmental resection with localization = 0=15%

Blind segmental resection = 75%

Subtotal colectomy = 0-40%

Question 27

Outline P/E for LGIB

Answer 27

General examination:
□ Anaemia: pallor, tachycardia
□ Dehydration: capillary refill time, dry tongue
□ Any extra-abd manifestation of IBD

Abdominal examination: usually normal
□ Mass
□ Tenderness

Digital rectal examination + proctoscopy:
□ Confirm haematochezia
□ Look for any anorectal pathologies, eg. haemorrhoids,
fissure-in-ano, masses

Question 28

Therapeutic colonoscopy is effective in management of which LGIB

Answer 28

Angiodysplasia

Diverticular disease

Post-polypectomy bleeding/ post-polypectomy coagulation syndrome*

(* development of abdominal pain, fever, leukocytosis, and peritoneal inflammation in the absence of bowel perforation after polypectomy with electrocoagulation)

Question 29

CT angiography for LGIB

• Advantages
• Indication
• Function

Answer 29

• Advantages: Fast, Non-invasive, higher precision, higher diagnostic yield than colonoscopy
• Indication: Hemodynamically unstable, shock index >1, active bleeding
• Function: Localize site of bleeding loss before planning endoscopic or radiological therapy

Question 30

Angiography for LGIB

• Procedure
• Detection sensitivity
• Diagnostic yield
• Complications
• Therapeutic techniques? recommended?

Answer 30

Procedure:

• Selective catherization of SMA, IMA and Celiac artery by Seldinger technique
• Observe extravasation of contrast

Detection: 1-1.5mL/min bleed

Diagnostic yield: Poorer than CT angiography and Ccolonscopy (27-67%)

Complications: Contrast allergy, renal failure, bleeding from puncture site

Therapeutic angiography: for embolization to stop bleeding, or injection of vasopressin

Not recommended, risk of bowel ischemia and infarction, vasopressin with cardiac S/E

Question 31

Radionucleotide scan for LGIB

• Types
• Advantages
• Disadvantages

Answer 31

Tc-99 labeled sulphur colloid, tag RBC

Labeled RBC not cleared rapidly and not taken up by liver and spleen

Advantages: High sensitivity (0.1mL/min)

Disadvantages: No therapeutic value, Less specific/ cannot localize precisely

Question 32

IBD

Compare 2 major type morphology/ histology

Answer 32

Question 33

Compare clinical features between Crohn’s and UC

Answer 33

Crohn’s

• Abdominal pain
• Diarrhea
• Weight loss
• Malaise, anorexia, fever
• Extra-intestinal manifestations: Uveitis, arthritis, ankylosing spondylitis, sclerosing cholangitis…etc

UC:

• BLOODY diarrhea with MUCUS
• Lower abdominal pain
• Milder malaise, anorexia
• Extra-intestinal manifestations: similar to Crohn’s

Question 34

Compare complications between Crohn’s and UC

Answer 34

Crohn’s

• Strictures - IO
• Fissures - perforation
• Fistula with nearby structures: urinary bladder, vagina, anal…etc
• Colorectal cancer

UC

• Toxic megacolon and rupture
• Colorectal cancer

Question 35

Modalities to localize small bowel bleed presenting as LGIB

Specify extent of examined GIT in each modality

Answer 35

Enteroscopy modalities

• Push enteroscopy: beyond DJ flexure
• Single/ Double balloon enteroscopy: entire small bowel
• Intra-operative enteroscopy: entire small bowel
• Capsule video capture: entire GIT

Question 36

Intraoperative endoscopy for LGIB

• Indication
• Procedure
• Routes of insertion

Answer 36

• Indication: prior localizations not made/ emergency
• Procedure: Foley catheter inserted through appendicostomy or enterotomy, bowel preparation by on-table antegrade irrigation, effluent from anus
• Routes of insertion: Transanal, Peroral, Through enterotomy, Laparoscopic assisted

Question 37

Causes of massive UGIB and Small bowel bleed that lead to LGIB

Answer 37

Massive Upper GIB: Peptic ulcer, variceal bleed

Small bowels (~5%)
Diverticulum: Meckel’s*, jejunoileal diverticula
Vascular lesions: angiodysplasia, haemangioma
Small bowel tumours
Small bowel ulcers: NSAID-induced
Enteritis: Crohn’s disease, TB
Aortoenteric fistula