Small Bowel Obstruction

Question 1

Is small bowel or large bowel obstruction more common?

Answer 1

Small bowel (60-75% cases)

Question 2

Bowel obstruction results in a build up of gas and faecal matter _____ to the obstruction causing d____ of intestines and v______

Answer 2

proximal
dilation
vomiting

Question 3

True or false: bowel obstruction is a surgical emergency?

Answer 3

True

Question 4

The GI tract secretes fluid that is later absorbed in the ____. In obstruction can’t reach colon and cannot be reabsorbed so there is a loss of fluid from the i______ s____ to the GI tract

Answer 4

Colon
intravascular space

Question 5

What is the abnormal loss of fluid from the intravascular space into the GI tract in a bowel obstruction referred to as?

Answer 5

Third-spacing

Question 6

The _____ the obstruction in the intestine, the greater the fluid loss

Answer 6

higher

As less bowel over which the fluid can be reabsorbed

Question 7

What can the fluid loss in a bowel obstruction lead to?

Answer 7

Hypovolaemia and shock

Question 8

What are causes of small bowel obstruction?

Answer 8

Adhesions
Hernias (strangulating)
Tumours
Strictures eg from Crohn’s
(Hirschsprung disease, affects colon)

Question 9

What is Hirschsprung disease?

Answer 9

Congenital malformation
No nerve supply in colon so can’t excrete properly (sensory information promotes bowel movement)

Question 10

What are causes of adhesions which in turn cause small bowel obstruction?

Answer 10

(Scar tissue that bind abdominal contents together)
Surgery
Endometriosis
Peritonitis
Abdominal/pelvic infections

Question 11

Is a bowel obstruction is suspected, what questions should be asked to gain information about potential cause?

Answer 11

Any previous abdominal surgery? (adhesions)

Any hernias?

Any change in bowel habit, weight loss, PR bleeding? (tumour)

Question 12

What are symptoms of small bowel obstruction?

Answer 12

Vomiting followed by constipation
Mild abdominal distension and pain
Tinkling bowel sounds

Question 13

True or false: there are hyperresonant bowels on percussion in SBO

Answer 13

True

Question 14

How is small bowel obstruction diagnosed?

Answer 14

1st line:
XR showing dilated bowel loops and transluminal fluid-gas shadows

Gold standard:
CT abdominal

Question 15

What is treatment for small bowel obstruction?

Answer 15

Fluid replacement (drip)
NG tube (drain)
Antiemetics and analgesia
Antibiotics as high infection risk

Last resort = surgery

Question 16

What is pseudo obstruction of bowel?

Answer 16

No mechanical obstruction
Often result of post-op state
eg from opiate induced paralytic ileus