Intestinal Obstruction

Question 1

Intraluminal causes

Answer 1

Gall stones
Foreign body
Faecal impaction

Question 2

Intramural

Answer 2

Cancer
Stricture - Crohn’s disease
Intussusception
Diverticula strictures

Question 3

Extramural causes

Answer 3

Hernias
Adhesions
Bands
Volvulus

Question 4

Small bowel obstruction causes (HANG IVS)

Answer 4

Hernia 
Adhesions - most common cause 
Neoplasms 
Gallstone ileus 
Intussusception 
Volvulus 
Strictures

Question 5

Large bowel obstruction causes (HAS CVD)

Answer 5

Hernia 
Adhesions (less common) 
Severe faecal impaction 
Colon cancer - Most common 
Volvulus 
Diverticula disease

Question 6

Symptoms of small bowel obstruction

Answer 6

Complete constipation
Crampy, intermittent abdominal pain
Nausea and vomiting - bile (early sign)
Abdo distension

Proximal bowel obstructions - present earlier

Question 7

Symptoms of large bowel obstruction

Answer 7

Complete constipation
Constant abdominal pain
Nausea and vomiting- faeculent - late sign
Abdominal distension

Distal constructions tend to present later with abdominal distension and constipation

Question 8

Signs of bowel obstruction

Answer 8

Tinkling bowel sounds
Abdominal tenderness
Signs of peritonism if perforation or vascular compromise:
- guarding
- rebounds tenderness
- rigidity
- shock - tachycardia, tachypnoea, hypotension

Question 9

Investigations

Answer 9

Abdominal exam
Obs
Bloods - FBC, U+Es, LFTs, CRP, Group + Save
VBG - ischaemia can cause acidosis (high lactate)

First line: AXR
Definitive diagnosis: CT

Question 10

Small bowel signs on AXR

Answer 10

Dilate bowel - 3+ cm
Proximal bowel dilation and distal bowel collapse
Valvulae conniventes visible
Central

Question 11

Large bowel signs on AXR

Answer 11

Dilation - 6+ cm
Haustra - not crossing whole length
Peripheral

Question 12

Intestinal obstruction management

Answer 12

Medical emergency
Drip and suck:
- nill by mouth and insert NG tube - suck
- IV Fluids - drip

Urinary catheter
Analgesia

Question 13

When is surgical Mx indicated

Answer 13

Signs of bowel compromise - ischaemia or perforation
Causes that require surgical intervention
- strangulated hernia
- tumour
If pt fails to improve after 48 - 72hrs

Question 14

Complications

Answer 14

Bowel ischaemia - stasis of fluid and contents proximal to obstruction causes bowel wall oedema which compresses vessels

• infarction and necrosis
• perforation
• peritonitis
• sepsis

Question 15

Causes of adhesions

Answer 15

Abdominal or pelvic surgery
Peritonitis
Infection - PID
Endometriosis