Bowel Obstruction ☺️

Question 1

What are the most common causes of bowel obstructions

Answer 1

Small bowel – adhesions, herniae

• Crohns
  
  • hot <= active inflammation causes strictures
  • cold <= repeated inflammation causes strictures
• Gallstones - repeated cholecystitis => fistula from GB to SB

Large bowel – malignancy, diverticular disease, and volvulus

Question 2

Presentation

Answer 2

Peristalsis against blackage =>

• Diffuse, central colicky abdo pain
• N+V (ask patient to describe the contents - billous/green)

Inability to pass anything

• constipation (reduced mv)/complete constipation (no stool or flatus)
• abdominal distension - particularly with LBO

Tinkling bowel sounds - more common in early BO
Tympanic on percussion
Tender

Question 3

Investigations

• bloods
• scans

Answer 3

IF BO SUSPECTED - URGENT BLOODS

• FBC
• CRP
• U&E - monitor for electrolyte losses, metabolic derangement
• LFT
• G&S
• VBG - high lactate => hypoperfusion and ischemia

CT scan with IV contrast - abdo, pelvis
  SBO
-dilated bowel 3cm+
-central
-visible valvulae conniventes
  LBO
-dilated bowel 6cm+, 9cm+ at cecum
-peripheral
-haustra (halfway across)

AXR
-free air under diaphragm

Question 4

Management

-

Answer 4

Initial
-NBM, IV fluids

Conservative

• NG drainage + urinary catheter - drip and suck
• If not - gastrograffin to see if contrast reaches LB in 6hrs

Surgery => laparotomy
-when no past abdo surgery - unlikely to resolve
-suspicion of intestinal ischaemia/closed loop bowel obstruction
-strangulated hernia, obstructing tumour
-no improvement in 48hrs+ with conservative
If resection needed, re-joining of obstructed bowel is often not possible => stoma

• IV ABx - esp if perforation suspected
• urinary catheter - reduce urinary distention for surgery

Question 5

Complications

Answer 5

Bowel ischaemia
Bowel perforation => faecal peritonitis
Dehydration and renal impairment