Bowel obstruction

Question 1

Imaging Investigations for BO

Answer 1

Erect or LL decubitus CXR
Erect and supine AXR
CT with water soluble contrast

If LBO suspected - water soluble enema (avoid barium as it may thicken and worsen the obstruction)

Question 2

General investigations for BO

Answer 2

CBC
UnE
ABG - metabolic alkalosis due to vomiting
Amylase

Question 3

Causes of small bowel obstruction

Answer 3

Top 3
Adhesions (75%)
Incarcerated or strangulated hernia
Malignancy

Other
Intraluminal
-Intussusception
-Gallstone ileus

Intramural
-Crohns
-Radiation stricture
-Adenocarcinoma

Extramural
-Adhesions
-Incarcerated hernia
-Peritoneal carcinomatosis

Question 4

Causes of large bowel obstruction

Answer 4

Top 3
Cancer
Diverticulitis
Volvulus

Intraluminal
-Faecal impaction

Intramural
-Adenocarcinoma
-Diverticulitis (Not usually the acute setting, but rather the associated stricturing and fibrosis from long-standing, recurrent
diverticulitis)
-IBD stricture (Crohn’s and less commonly UC)
-Radiation stricture

Extramural
-Volvulus
-Adhesions