Intestinal obstruction

Features of obstruction:

• Anorexia

• Nausea/vomiting

• Colicky abdominal pain with abdominal distension

• Constipation (although need not be absolute if obstruction is high)

• Active ‘tinkling’ bowel sounds

Is the obstruction small or large bowel?

1. Small bowel:

• Supine AXR shows central gas shadows with NO gas in the large bowel

• Vomiting occurs earlier

• Less abdominal distension

• Pain is higher in the abdomen

2. Large bowel:

• Supine AXR shows gas proximal to the obstruction

• Constant pain

Is there ileus or mechanical obstruction?

Ileus = functional obstruction due to decreased bowel motility

• In ileus: - There is no pain

- Absent B/S

Is the bowel strangulated?

Signs:

• Pt is more ill than you would expect

• Pain is sharper and more constant than the central colicky pain of the obstruction.

• Localized pain

• Peritonism

• Fever/inc WCC (occasionally)

Causes:

1. Small bowel:

• Adhesions (common)

• Hernias (common)

• Crohn’s disease

• Gallstone ileus

• Tumour

• Intussusception (only in infants <18mths)

2. Large bowel:

• Tumour (common)

• Diverticulitis (common)

• Faeces

• Sigmoid/caecal volvulus (twisting of part of the gut)

Intestinal obstruction

Management:

1. Conservative:

• Pass NG tube

• IV fluids to rehydrate and correct electrolyte imbalances

2. Surgery:

• Strangulation requires urgent surgery (<1h), as does large bowel obstruction with gas dilatation (>8cm) and tenderness over the caecum (as perforation as close).

• For less urgent large bowel obstructions, there is time for an enema to try to clear the obstruction and correct fluid imbalance.