Obstruction

Question 1

How big are the large and small bowel normally?

Answer 1

Small Bowel - 2.5cm

Large Bowel - 6cm

Question 2

At what size are the large and small bowel considered to be dilated?

Answer 2

Small bowel lumen > 3 cm
Large Bowel Lumen > 6 cm
Caecum Lumen > 9 cm

Question 3

What are the main signs and symptoms of large bowel obstruction?

Answer 3

Absolute constipation
Vomiting (late stage)
Abdominal distention
Loud normal bowel sounds
Non tender abdomen
Empty rectum

Question 4

How is large bowel obstruction managed?

Answer 4

Conservatively - drip and suck

fluid resuscitation and intestinal decompression or stenting endoscopy

Question 5

How would a competent ileo-caecal valve affect large bowel obstruction?

Answer 5

Fluids and materials can pass in but not out meaning the large bowel distends rapidly and the caecum will rupture causing peritonitis

If incompetent, small bowel will also distend so perforation isnt as big a risk

Question 6

How does small bowel obstruction present?

Answer 6

Colicky umbilical pain
Vomiting - pain relief
Abdominal distention
Tinkling bowel sounds
Palpable loops of bowel

Question 7

How is small bowel obstruction managed?

Answer 7

Drip and suck - fluid resus and tube for decompression

Watch and wait as may need laparotomy

Question 8

What is a complication of small bowel obstruction?

Answer 8

Strangulated obstruction when blood supply become impaired –> ischaemia and gangrene within 6hrs of onset