Approach to Bleeding Lower GIT Flashcards
Define LGIB
bleeding that originates from a source distal to the Ligament of Treitz.
The ligament of
Treitz is the suspensory muscle of the duodenum that connects the DJ flexure to the connective tissue surrounding the celiac axis
and SMA .
Clinical presentation of LGIB
Hematochezia
-gross and freash blood seen either on toilet
paper after defecation or mixed with stools.
What do you need to further ask about the PR bleeding ?
Was it noticed on wiping, having blood drip into the toilet bowl, frank blood on defecation?
▪ Noticed on wiping: suggestive for anal fissures (usually have pain as well)
▪ Having blood drip into toilet bowl / blood coating stools: suggestive for hemorrhoidal bleeding
▪ Coating stools: suggests distal bleed
▪ Mixed in with stools: suggests proximal bleed
What is the colour of the PR bleeding? Frank red blood, maroon coloured blood, melena?
▪ The colour of the blood give suggestion to the anatomical location, the amount and speed of bleeding also affects the
colour – It takes ~14 hours for blood to be broken down within the intestinal lumen; if transit time is < 14 hours the
patient will exhibit hematochezia, and if > 14 hours patient will exhibit melena.
▪ Frank red bleeding: suggestive of blood originating from left colon
▪ Maroon colored bleeding: suggestive of blood originating from right colon (may be mixed with stools)
▪ Melena: suggestive of UBGIT or occasionally from right sided colonic bleed
▪ Ask if stools are foul-smelling, sticky, and as black as hair.
▪ Melena is seen as black tarry stools resulting from oxidation of hematin (altered blood) in the GIT
What are the associated symptoms you want to ask ?
▪ Pain on defecation: suggestive of anal fissure, rectal tumours (i.e. tenesmus– incomplete defecation, recurrent
inclination to defecate, frequently painful), ischemic colitis
▪ Bloody Diarrhoea: suggestive of infective causes, inflammatory bowel disease (diarrhoea mixed with blood & mucus)
▪ Abdominal pain with PR bleed: suggestive of colitis (inflammatory, ischemic, infective)
▪ Passing of mucus
▪ Hematemesis: suggestive of massive UBGIT
What is the red flags of malignancy you need to ask (CACAPO)
▪ Change in bowel habits such as alternating constipation and diarrhoea
▪ Any spurious diarrhoea ( mimic diarrhea - ask about mucus presence)
▪ Change in stool calibre such as pencil thin stools
▪ Any constitutional symptoms such as loss of weight and appetite
▪ Presence of tenesmus, which can be due to rectal tumours, infective colitis, inflammatory colitis and radiation proctitis
▪ Other risk factors: smoking, diet (i.e. red meat), obesity
Potential complication from PR bleeding
▪ Any symptomatic anemia (i.e. SOB on exertion, postural dizziness, syncope, chest pain, palpitation, lethargy/fatigue),
▪ Any risk of cardiac complications from PR bleeding (i.e. any history of ischemic heart disease which increases patient
risk of acute myocardial infarction)
▪ Signs of Anaemia
▪ Face – (i) conjunctival pallor (ii) pallor of mucous membrane
▪ Cardiac Auscultation – short systolic flow murmur at aortic area
▪ Pulse – (i) tachycardia (ii) bounding (iii) collapsing pulse
▪ Hands – pallor of palmar creases
In term of social history , what do you want to ask
▪ Any Smoking, Alcohol intake, Obesity, Diet (i.e. red meat), these are known risk factors for CRC (SADO)
▪ Any recent travel history / positive contact history (infective colitis such as traveller’s diarrhoea, usually a/w fever)
Medication History , what do you want to know and why
▪ Any recent intake of NSAIDs (NSAIDs induced colitis)
▪ Any anti-platelets, anticoagulants, novel oral anticoagulants (NOACs) → bleeding diathesis
▪ Any antihypertensive medications
▪ Any iron supplementation → dark green stools mimicking melena
Differential diagnosis of LGIB
1) Angiodysplasia -vascular malformation in GIT that causes swollen or enlarged blood vessels and bleeding lesions ( more common in elderly)
2) Diverticular disease
3) Infective ( bacterial , Viral ,Parasitic)
Investigations
Biochemical Investigations
- FBC: keep Hb > 8-10 (know what is the baseline Hb), transfuse platelet if platelet < 50, assess TW if worried about colitis
- U/E/Cr: assessment of renal function (i.e. Cr / eGFR as may need contrasted scans), urea level (tend to be raised in UBGIT)
- PT/PTT: if patient has history of liver disease or on anticoagulants, KIV correct coagulopathy (NUH anticoagulation guidelines)
- GXM
- Cardiac Enzyme: to rule out cardiac event as a cx
- ABG/Lactate: useful in patients presenting with hemodynamic instability/hypovolemic shock
Colonoscopy
Imaging Investigations
Colonoscopy purpose
- Diagnostic – able to identify cancer (and biopsy for histology), diverticular disease, angiodysplasia etc.
- Therapeutic advantage: inject vasoconstrictive agents (epinephrine) or applying thermal therapy (laser photocoagulation,
heater probe) to control bleeding and/or mechanical interventions (i.e. endoclips)
Imaging investigation
- used if hemodynamically unstable. Has the advantage of the ability to diagnose bleeding throughout the
GI tract, including small bowel sources unreachable by colonoscopy. However, it requires active bleeding at the time of the study to detect the bleeding site.
CTMA ( CT Mesenteric Angiogram)
▪ Contrasted scan that can detect bleeding as low as 0.3 mL/min
▪ When active bleeding is present, it can provide precise anatomical location of bleed in 90% of the time based on where
there is active contrast extravasation in the bowel lumen
▪ Disadv: No therapeutic intervention, radiation exposure, use of IV contrast that risks nephropathy & allergy
Followed by selective Mesenteric Angiography
Principle of management
Resuscitation and hemodynamic stabilization, identify site of bleeding, treat accordingly
resuscitation - goal to normalize the blood pressure and heart rate
