Intestinal Obstruction

Question 1

What is intestinal obstruction?

Answer 1

Mechanical bowel obstruction

Question 2

Can mechanically obstruct:

Answer 2

Small bowel (65 - 75% all cases)
Large bowel (25 - 40% all cases)

Question 3

What causes small bowel obstruction?

Answer 3

Adhesions (mc) - post surgical (stick together)
Crohns
Strangulating hernias
Malignancy

Question 4

What causes large bowel obstruction?

Answer 4

Malignancy (90%)

Volvulus - twisting of bowel (mostly sigmoid colon, children)

Intusseption - bowel telescopes in on itself , MC in children

Question 5

Symptoms of small bowel obstruction

Answer 5

First vomit then constipation

Mild abdo distension + pain (crampe central pain)

Tinkling bowel sounds (+ hyper resonance bowels on percussion in both SBO/LBO)

Question 6

Symptoms of large bowel obstruction

Answer 6

First constipation then vomiting

Gross distension + pain (spasms, longer lasting + lower abdo)

Hyperactive then normal, them absent bowel sounds

Question 7

Dx in both?

Answer 7

1st line = X ray shows dilated bowel loops + transluminal fluid, gas shadows
(‘gas fluid levels’ - fluid and air accumulate in bowels here - this is a good diagnostic sign of SBO/LBO)

GS = CT abdo with contrast - should be first line

Question 8

Tx of bowel obstruction?

Answer 8

Fluid resus - IV Fluids
NG tube (feeding)
anti emetics + analgesia
Abx - ‘stasis is the basis’ - increased infection risk
Surgery last resort