Intestinal obstruction & ileus

Question 1

What is intestinal obstruction

Answer 1

Mechanical disruption in the patency of the GI tract and flow of intestinal contents, resulting in a combination of emesis, absolute constipation and abdominal pain

Question 2

What is ileus

Answer 2

slowing of gastrointestinal motility accompanied by distention, in the absence of a mechanical intestinal obstruction

Question 3

What are the causes of small bowel obstruction

Answer 3

Duodenal atresia
Jejunal/ileal atresia or stenosis
Malrotation of the gut + volvulus
Meconium ileus
Intussusception
Strangulated inguinal hernia
Meckel’s diverticulum

Question 4

What are the causes of large bowel obstruction

Answer 4

Meconium plug
Hirschsprung’s disease
Anorectal malformation: imperforate anus
Intussusception
Strangulated inguinal hernia

Question 5

What are the causes of ileus

Answer 5

Paralytic ileus:
Gastroenteritis
Electrolyte imbalance e.g. hypokalaemia
Abdominal surgery
Reduced blood supply to intestines

Question 6

What are the signs and symptoms of intestinal obstruction

Answer 6

Persistent bile stained vomiting
Delayed meconium passage
Abdominal distension
Abnormal bowel sounds

The more proximal the obstruction, the more prominent the vomiting and the sooner it becomes bile-stained (unless the obstruction is proximal to the ampulla of Vater)
The more distal the obstructions are more likely to cause significant abdominal distension

Question 7

What investigations should be done for intestinal obstruction and ileus

Answer 7

Bedside: urine dip, stool culture, fecal calprotectin
Bloods: FBC, U&Es, CRP/ESR, calcium and bone profile, TFTs
Imaging: AXR

Question 8

What do findings on AXR for obstruction suggest

Answer 8

Few dilated loops of bowel: proximal obstruction e.g. malrotation, jejunal atresia
Multiple dilated loops of bowel: distal obstruction e.g. ileal atresia, meconium ileus or plug, Hirschsprung’s or anal atresia

Question 9

What is the management for intestinal obstruction

Answer 9

1. IV fluid and electrolyte correction
2. Treat the cause:
   Atresia/stenosis: duodenoduodenostomy or laparotomy with primary resection and anastomosis (Jejunal)
   Malrotation: Ladd’s proceudre
   Meconium ileus: gastrograffin contrast, surgical decompression
   Hirschsprung’s: rectal washout/bowel irrigation
   Necrotising enterocolitis: Conservative and supportive for non perforated cases, laparotomy and resection in cases of perforation of ongoing clinical deterioration

Question 10

What are the complications of intestinal obstruction

Answer 10

Small Bowel Obstruction:
- Intestinal ischaemia → infarction → necrosis → perforation → peritonitis
- Sepsis
- Multi-organ failure
- Intra-abdominal abscess
- Short bowel syndrome

Large bowel:
- Intestinal ischaemia → infarction → necrosis → perforation → peritonitis
- Sepsis
- Death

Question 11

What is the prognosis for intestinal obstruction

Answer 11

SBO is medical emergency, and those who are treated in a timely manner have a very good prognosis
SBO is a major cause of morbidity and mortality, and it can be fatal in untreated patients due to its progression to intestinal necrosis, perforation, sepsis, and multi-organ failure.

Question 12

What are the features of duodenal atresia/stenosis and what investigations should be done

Answer 12

Associated with Down’s syndrome (1/3) and other congenital malformations
AXR: double bubble sign
Contrast study for diagnosis

Question 13

What are the features of jejunal atresia/stenosis and what investigations should be done

Answer 13

Multiple atretic segments of the bowel
AXR: air fluid levels

Question 14

What are the features of meconium plug and what investigations should be done

Answer 14

Plus of inspissated meconium causing lower intestinal obstruction
Usually passes spontaneously

Question 15

What is meconium ileus and what investigations should be done

Answer 15

Thick inspissated meconium, putty-like consistency
Becomes impacted in the lower ileum
Associated with cystic fibrosis
Delayed passage of meconium and abdominal distension

AXR: no fluid levels as meconium is viscid
PR contrast studies: may be therapeutic
Sweat test to confirm CF

If no response to PR contrast and NG N-acetyl cysteine -> requires surgery to remove plugs

Question 16

What is meckel’s diverticulum and its rule of 2s

Answer 16

Congenital malformation of the bowel which causes painless massive rectal bleeding in children 1-2yo

(1 to) 2-years-old
2% population
2x more common in boys
2 feet from ileocecal valve
2 inches long
2 different mucosae (gastric and pancreatic)

Question 17

What causes meckel’s diverticulum

Answer 17

2% of people have an ileal remnant of the vitello-intestinal duct (also known as omphalomesenteric duct)- a long narrow tube that joins the yolk sac to the midgut lumen of the developing foetus
It contains either gastric mucosa or pancreatic tissue i.e. can form gastric ulcers caused by acidity that bleed
The acid produced within the pouch can be released/ spilled causing ulcers or peritonitis

Question 18

What are the signs and symptoms of meckel’s diverticulum

Answer 18

Most asymptomatic
Rectal bleeding - severe (neither bright red or true melaena) -> may cuase haemodynamic instability
May have intractable constipation
Intussusception, volvulus, meckel’s diverticulitis (mimics appendicitis)
Bowel obstruction -> cramps, pain, tenderness
Nausea and vomiting

Question 19

What are the differentials for meckel’s diverticulum

Answer 19

Appendicitis - unlikely to have rectal bleeding, pt will be febrile & N+V
Intusception - peak age around 9m, will have colic pain and inconsolable crying
Anal fissure
Polyp
Clotting disorder
Peutz-Jeghers syndrome is a rare autosomal dominant disorder that is characterised by hamartomatous polyposis. Gastrointestinal symptoms first start becoming apparent at around 10 years of age. 

Question 20

What investigations should be done for meckel’s diverticulum

Answer 20

Abdo exam
Bedside: stool sample
Bloods: FBC
Imaging: USS, XR, Meckel’s scan
- A Technetium scan (Meckel’s Scan): increased uptake by ectopic gastric mucosa in 70% of cases
- Used if the child is haemodynamically stable with less severe or intermittent bleeding 

Question 21

What is the management for Meckel’s diverticulum

Answer 21

Asymptomatic (Incidental imaging finding)
NO treatment required
Detected during surgery for other reasons- prophylactic excision

Symptomatic
Bleeding- excision of diverticulum with blood transfusion (if haemodynamically unstable)
Obstruction- excision of diverticulum and lysis of adhesions
Perforation/ peritonitis- excision of diverticulum or small bowel segmental resection with perioperative antibiotics
Surgery usually performed laparoscopically

Question 22

What are the complications of Meckel’s diverticulum

Answer 22

Haemorrhage
Intestinal obstruction
Umbilico-ileal fistulas
Perforation

Question 23

What is the prognosis of Meckel’s diverticulum

Answer 23

Excellent if treated in a timely fashion
Most common complication is post-operative bowel obstruction (due to adhesions)