Rectal bleeding

Question 1

What clinical features could suggest haemodynamic instability?

Answer 1

hypotension, tachycardia, cool peripheries, tachypnoea, or

decreased consciousness

Question 2

T/F upper GI bleeds never present with rectal bleeding alone

Answer 2

F

upper GI sources of haemorrhage
may occasionally present with rectal bleeding alone. Whilst it is more likely that
such upper GI sources will also present with haematemesis, you should note that
large volumes of blood in the GI tract can act as a cathartic (stimulant of peristalsis)
and the resultant rapid transit through the intestine leads to the passage of red blood
per rectum.

Question 3

T/F upper GI bleeds will only present with black stools due to malaena

Answer 3

F
Substantial bleeding from lesions proximal in the
GI tract may present with melaena (jet black liquid stool caused by bacterial
oxidation of haem) or may present as frank blood (haematochezia) if transit
times are suffi ciently rapid.

Question 4

What would each of the following relationships of blood to the stools suggest:

• Blood mixed in with stool
• Blood streaked on stool
• Blood separate from stool
• Blood only on toilet paper

Answer 4

1. Mixed in: suggests a lesion PROXIMAl to the sigmoid colon, by which point the stool is too hard for any blood to mix in with it
2. Streaked on stool: suggests sugmoid/anorectal source of bleeding
3. Blood separate from stool: if immediately after stool suggests anal condition like haemorrhoids. If, however, blood is passed on its own, this implies that there has been
   suffi cient bleeding to dilate the rectum and produce a defecation stimulus.
   Such bleeding is most likely to occur with diverticular disease, angiodysplasia, infl ammatory bowel disease, or sometimes a rapidly bleeding cancer
4. Blood is only seen on the toilet paper: this implies relatively minor
   bleeding from the anal canal, most likely due to haemorrhoids or an anal
   fissure.