GI - Rectal bleeding investigations Flashcards
(4) types of rectal bleeding
- overt red bleeding
- malaena
- massive/acute bleeding
- occult bleeding
What is massive/acute rectal bleeding?
- consequence
- prognosis
- sources
Substantial bleeding that creates haemodynamic instability -> requires admission & transfusion.
Early cessation usual but 15% continue to bleed/rebleed.
Most cases due to a (right sided) colonic source; diverticular disease, angiodysplasia.
Up to 25% cases due to small bowel pathollogy.
Occasional cases due to rectum: due to briskly bleeding GI problem.
A negative nasogastric tube aspirate when looking for stomach bleeding:
does not rule out bleeding from the stomach. the blood may have clotted and unable to be aspirated.
Mx of massive/acute rectal bleeding
- resuscitation
- reversal of anticoagulation
- elective colonoscopy
- CT angiogram, nasogastric tube, sigmoidoscopy,
Describe occult bleeding
- screen detected (FOB)
- can Px as anaemia (severe menorrhagia, coeliac, vegans, alcoholics, carcinoma of caecum, poor nutrition)
- colonoscopy is mandatory for both
- other tests if colonoscopy negative
*Fecal occult blood test is a screening tool and NEVER a diagnostic test
Causes of overt rectal bleeding
Anorectal: haemorrhoids, fissure
Colorectal: cancer, plyps, colitis
Causes of anaemia
severe menorrhagia, coeliac, vegans, alcoholics, carcinoma of caecum, poor nutrition, GI bleeding, any blood loss
Appearance of rectal prolapse
4-6cm in length, eccentric, one sided, rounded
What are haemorrhoids?
- structure
- Px
- worse with…
- Rx
bunch of arterioles (NOT venous c.f. rectal venous varices in portal HTN).
May bleed, prolapse or thrombose.
Blood is bright red in the toilet bowl/paper, not mixed in the stool.
Worse when constipated & straining.
Rx: high fibre diet (15g/day) first line. If failed, consider banding/surgery.
Describe anal fissure
- Px
- 2 types of pain
- Px: rectal bleeding (usually less than haemorrhoids)
- common, very painful
- 2 types of pain: severe sharp tearing pain on defecation & dull ache for 1-2 hours afterwards (muscle/sphincter spasm)
Appearance of bowel cancer inside bowel.
- Px
- colour of blood
Mass lesion, everted edges, central ulceration
Can Px with bright rectal bleeding but usually DARK red bleeding + blood within the stool.
Malignant bowel bleeding is dark, as they invade veins.
Describe anal wart
- cause
- anal cancer type
- Rx
Due to HPV
Anal cancer is SCC (tiny proportion of GI malignancy)
Rx: radiotherapy + chemotherapy WITHOUT surgery. Better prognosis (80% cure rate)
What should you ask in a rectal bleeding Hx?
- colour of blood
- anorectal symptoms (pain, anal swelling)
- colorectal symptoms (change in bowel habit, unsatisfied defaecation, passage of mucus)
- how long
- FMHx
How do you do an anal inspection?
- good lighting
- left lateral
- slow gentle movements (even parting the buttocks can hurt a fissure pt)
- look for: fissures, haemorrhoids, thrombosed perianal haematomas, fistula, warts, anal cancer
How do you perform a DRE?
Use pulp not tip of finger, gentle.
Contemplate:
- character of mucosa
- presacral space
- gently increasing pressure can reach 10cm in most
- cervix can be a trap (the rectal mucosa is normal overlying the hard cervix)
- feel for prostate
- check for blood on the glove
What rectal bleeding should you be concerned about?
- colour
- stool
- mucus
- change in bowel habits
- age
- FMHx
- dark marroon
- mixed
- mucus present
- change in bowel habits
- > 40yo
- FMHx positive
How does R colon cancer present?
Anaemia, mass
How does L. colon cancer present?
- alternating constipation and diarrhoea
- constipation only
- colicky lower abdo pain
- dark blood in stool
How does rectal cancer present?
- rectal bleeding; dark but sometimes bright
- unsatisfied defaecation
- passage of mucus
Prognosis of bowel cancer
Five year survival depends on ACPS grading (A-D) ranges from 90% to 5%.
Indications for colonoscopy
- rectal bleeding: persistent, dark bleeding, >40yo
- change in bowel habit
- iron deficiency anaemia
- screening: positive FOBT
- surveillance: e.g. positive FMHx
How do you Rx anal fissure?
GTN in anus. 3 times a week for 3 weeks -> review.
See if symptoms have resolved, if not, look further for any other causes of bleeding e.g. colonoscopy
Bowel cancer screening in Australia currently
5 yearly fecal occult blood test (FOBT) from 50yo. (but the evidence is every 2 yearly) -> 2 yearly test from 2020.
$7 per test
