Bowel obstruction

Question 1

Which is more common… small or large bowel obstruction?

Answer 1

Small bowel obstruction (SBO)

Question 2

What are the causes of bowel obstruction?

Answer 2

The “big three” causes account for around 90% of cases of bowel obstruction:

• Adhesions
• Hernias
• Tumours

Question 3

Describe the clinical features of bowel obstruction

Answer 3

• Abdominal distension and pain
• Nausea and vomiting (typically bilious)
• Absolute constipation and lack of flatulence

Question 4

What may you hear on auscultation of the abdomen in a patient with bowel obstruction?

Answer 4

“Tinkling” bowel sounds

Question 5

Give one potential complication of bowel obstruction?

Answer 5

Perforation

Question 6

What may you find on a blood gas in a patient with bowel obstruction?

Answer 6

• Metabolic alkalosis (as a result of vomiting)

- Raised lactate (bowel ischaemia)

Question 7

Describe the initial management of bowel obstruction

Answer 7

• Nil by mouth (NBM)

- “Drip and suck” (IV fluids and NG tube)

Question 8

a) Which imaging is initially performed in a patient with suspected bowel obstruction? Describe the key finding in bowel obstruction
b) Which investigation is usually done after this?

Answer 8

a) Abdominal XR - showing distended loops of bowel

b) Contrast abdominal CT scan - to confirm the diagnosis and establish a site/cause for the obstruction

Question 9

Describe the definitive management of bowel obstruction - how can the management options be classified?

Answer 9

Conservative:
- “Drip and suck” alone (where this fails, surgery is required)

Surgical:

• Adhesions = adhesiolysis
• Hernia = hernia repair
• Tumour = emergency resection

Stenting:
- Stents may be inserted into the bowel during colonoscopy in patients with an obstruction secondary to a tumour if patient is not fit enough for surgery (i.e. palliative cases)