Presentation, Diagnosis and treatment of bowel obstruction

Question 1

which part dilates in relation to an obstruction?

Answer 1

proximal to the obstruction

distal to obstruction = collapsed

Question 2

how does composition of vomit indicate placement of obstruction?

Answer 2

bile = distal to ampulla of vater
semi digested food = gastric
more fully digested, brown = further down

Question 3

what are some symptoms of bowel obstruction?

Answer 3

vomiting
pain
constipation
distension
complete obstruction
incomplete obstruction

Question 4

do symptoms develop more gradually in small or large bowel obstruction?

Answer 4

large

Question 5

what are the signs of an incompetent ileo-caecal valve?

Answer 5

small bowel distension as well as large

Question 6

higher chance of perforation if ileocaecal valve is competent, true or false?

Answer 6

true

Question 7

what changes occur in incomplete obstruction?

Answer 7

bowel wall hypertrophy

Question 8

physical signs of obstruction?

Answer 8

dehydration
abdominal distension
visible peristalsis
relative lack of abdominal tenderness
palpable mass in some
often resonant
"high pitched, tinkling bowel sounds"
may be no sounds
sometimes water sounds

Question 9

what might tenderness in obstruction indicate?

Answer 9

ischaemia

Question 10

bowel obstruction investigation?

Answer 10

supine AXR
- shows distension before obstruction and collapse after
- distended loops (small bowel lie in middle position, large bowel sits in normal place and haustra have coli)
Rarely erect AXR (would show fluid level)
CT

Question 11

how is bowel obstruction managed?

Answer 11

nil by mouth
IV cannula and send bloods
resuscitate with fluids, electrolytes
pass NG tube to decompress the stomach, stop vomiting, measure how much coming out

Question 12

what mechanical causes can result in bowel obstruction?

Answer 12

adhesions/bands (congenital/previous surgery)
incarcerated abdominal wall hernia
internal hernia
volvulus
.
.

Question 13

how are adhesion obstructions managed?

Answer 13

drip and suck

surgery sometimes

Question 14

what is the most common site for a volvulus?

Answer 14

sigmoid colon

most common in frail elderly

Question 15

how is a sigmoid volvulus managed?

Answer 15

untwist via colonoscope or sigmoidoscope

Question 16

what is the risk of dilation behind the obstruction?

Answer 16

can perforate causing peritonitis

Question 17

what are the most common causes of inflammatory strictures?

Answer 17

crohns

diverticulitis

Question 18

how does crohns cause bowel obstruction?

Answer 18

inflammation causes stricture

Question 19

what types of bolus can obstruct the bowel?

Answer 19

food bolus
impacted faeces
impacted gallstone ileus (rare)
trichobezoar (rare)

Question 20

how does gallstone ileus occur?

Answer 20

fistula between bile duct - duodenum
gallstone travels into small intestine
travels down and gets stuck at ileocaecal valve

Question 21

what is intussusception?

Answer 21

segment of bowel wall becomes telescoped into segment distal to it
usually initiated by mass in bowel wall (eg. hypertrophy)

Question 22

what is bowel strangulation?

Answer 22

when obstructed bit of intestine gets trapped
venous return is obstructed (as its very low pressure so doesn’t take much)
intravascular pressure rises until so high that arterial supply cant get into the bowel segment
can result in ischaemia - death of tissue

Question 23

name 2 types of adynamic bowel obstruction?

Answer 23

paralytic ileus

pseudo obstruction

Question 24

what is paralytic ileus?

Answer 24

failure of peristalsis
risks = recent surgery and ….
often painless but same symptoms as obstruction
treat with drip and suck until it sorts itself

Question 25

what is pseudo obstruction (Ogilivie’s syndrome)?

Answer 25

acute dilation of colon in absence of colonic obstruction in acutely unwell