Gastroenterology: Intussusception

Question 1

What is intussusception?

Answer 1

The invagination of proximal bowel into a distal segment

Question 2

What region is most commonly involved?

Answer 2

The ileum passing into the caecum through the ileocaecal valve

Question 3

Is it the most common cause of intestinal obstruction after the neonatal period?

Answer 3

Yes

Question 4

What is the peak age of presentation?

Answer 4

3 months to 2 years

Question 5

Does it affect more boys or girls?

Answer 5

Boys twice as often affected

Question 6

What features are associated?

Answer 6

Paroxysmal, severe colicky pain with pallor
- during episodes of pain, child becomes pale, especially around mouth and draws up legs
Vomiting - may become bile stained depending on site
Feed refusal
Sausage shaped mass in RUQ
Characteristic red current jelly stool - comprising blood stained mucus
Abdominal distension
Shock

Question 7

When does the passage of red current jelly stool occur?

Answer 7

Tends to be late in the illness and may be first seen after rectal examination

Question 8

What is the most serious complication?

Answer 8

Stretching and constriction of the mesentery resulting in constriction of venous drainage resulting in further swelling and interruption of arterial supply.

Bleeding from the bowel mucosa, fluid loss and subsequent bowel perforation, peritonitis and gut necrosis can occur

Question 9

Is an underlying intestinal cause of the intussusception often found?

Answer 9

No

Question 10

What theories are there regarding the cause?

Answer 10

Viral infection - enlargement of Peyer’s patches, which may form the lead point of the intussusception
Meckel’s diverticulum - can invert and stick back into intestine. Can then act as a lead point and drag ileum into caecum.

Question 11

Why is IV fluid resuscitation likely required immediately?

Answer 11

Often pooling of fluid in gut

Question 12

Why may hypovolaemic shock occur?

Answer 12

Due to pooling of fluid in the gut

Question 13

What investigations should be done?

Answer 13

USS - may show target like mass

Question 14

How is it managed?

Answer 14

Reduction by air insufflation under radiological control - only once child resuscitated and supervision of surgeon in case of perforation (not if peritonitis)

If this fails or signs of peritonitis - surgical reduction

Question 15

What is another term for intussusception?

Answer 15

Telescoping

Question 16

What risk factors are there?

Answer 16

Previous intussusception
Sibling with intussusception
Having intestinal malrotation

Question 17

Why can ischaemia occur?

Answer 17

Due to pressure on the wall of the trapped section of bowel - squeezes shut the small vessels running in wall of bowel. This can cause lack of blood flow to the tissue (ischaemia) and eventually infarction (death of tissue).

Question 18

Ischaemia leads to…

Answer 18

Sloughing off of intestinal mucosal tissue, blood and mucus into the gut - leading to red current jelly stool

Question 19

What can fever suggest?

Answer 19

The intestines perforated and leaking bacteria into the cavity - causing sepsis

Question 20

Why can volvulus occur as a result of intussusception?

Answer 20

The blockage prevents food passing, leading to a large mass, which can potentially cause intestine to become twisted

Question 21

What may an AXR show?

Answer 21

Distended small bowel and absence of gas in the distal colon