Bowel Obstruction

Question 1

Mechanical causes? (7)

Answer 1

adhesions
obstructed hernia
tumours
volvulus (sigmoid most common)
crohn's/diverticular disease, 
gallstone ileus
intussusception

Question 2

Paralytic ileus (lack of movement somewhere in the intestines) causes? (3)

Answer 2

post-operative ileus
electrolyte disturbances
pseudo-obstruction

Question 3

Large bowel obstruction causes? (2)

Answer 3

Colonic carcinoma

Diverticular stricture

Question 4

Presentation?

Answer 4

abdominal pain, distension, vomiting (facaes = sigmoid obstruction), constipation
history of severe pain = strangulation and ischaemia

Question 5

O/E?

Answer 5

fever, dehydration, shock, hernias, tinkling or absent bowel sounds. PR may show an empty rectum

Question 6

Investigations?

Answer 6

Bloods: FBC, U&E’s, LFT’s, glucose, amylase, clotting, G&S
CXR (erect): rule out perforation
Supine AXR

Question 7

AXR changes in small bowel obstruction?

Answer 7

Dilated small bowel:

Size: >3cm
Position: central
Mucosal/wall pattern: valvulae conniventes (thin/closely spaced/cross the entire width of the bowel)

Question 8

AXR changes in large bowel obstruction?

Answer 8

Dilated large bowel:

Size: >5.5 cm (>9cm for the caecum)
Position: peripheral location
Mucosal/wall pattern: haustral folds (thick, widely spaced/do not cross the entire width of the bowel)

Question 9

AXR changes in gallstone ileus?

Answer 9

Rigler’s triad:

Pneumobilia (gas in biliary tree)
Small bowel obstruction
Gallstone

Question 10

Mx?

Answer 10

ABCDE
Drip & Suck - NG tube (decompress bowel) and IV fluids 0.9% saline
IV opiod
cyclizine (50 mg)
Involve ICU