Small bowel disease

Question 1

What is the venous drainage of the majority of the small bowel?

Answer 1

Superior mesenteric vein

This joins the splenic vein to form the portal vein

Question 2

What is the nerve supply to the small bowel?

Answer 2

Sympathetic - splanchnic nerves
Parasympathetic - vagus nerve
Insensitive to most painful stimuli, but sensitive to distension

Question 3

What are the 4 layers of the intestinal wall?

Answer 3

Mucosa
Submucosa
Muscularis
Serosa

Question 4

What causes the vast majority of small bowel obstructions?

Answer 4

Adhesions

Hernias

Question 5

What are the extrinsic causes of small bowel obstruction?

Answer 5

Adhesions
Hernias:
   - External: inguinal, umbilical
   - Internal: diaphragmatic
Neoplastic
Intra-abdominal sepsis/abscess

Question 6

What are the causes of small bowel obstruction that occur in the bowel wall?

Answer 6

• Congenital: malrotation, cystic fibrosis, Meckel’s diverticulum
• Inflammatory: Crohn’s diseases
• Infectious: TB, actinomycosis
• Traumatic: haematoma, ischaemic stricture
• Neoplastic: primary, metastatic
• Other: intussusception, endometriosis, radiation stricture

Question 7

What are the causes of small bowel obstruction that occur in the lumen?

Answer 7

Gallstone (ileocaecal valve)
Bezoar
Foreign body
Enterolith

Question 8

Clinical signs of small bowel obstruction

Answer 8

• Gaseous distension
• Previous surgical scars (adhesions)
• Early vigorous peristalsis - later silent
• Masses
• Supraclavicular lymph nodes
• Localised rebound tenderness and guarding suggest perforation
• Irreducible hernia
• Blood or masses on rectal examination

Question 9

What is the radiological diagnosis of SBO?

Answer 9

• Plain film abdominal X-ray
• Dilated loops of small bowel (>3cm)
• Absence of dilated large bowel

Question 10

What does free air under the diaphragm on CXR indicate?

Answer 10

Perforation of a hollow viscus organ

Question 11

Management of SBO?

Answer 11

• Aggressive fluid resuscitation
• Abx cover if perforation suspected
• NG tube to drain stomach contents as much as possible
• Urinary catheter
• Exclude non-mechanical bowel obstruction

Question 12

Common contraindications to surgical management of SBO?

Answer 12

• Adhesive obstruction
• Paralytic ileus
• Crohn’s disease
• Abdominal carcinomatosis

Question 13

Management of adhesive SBO?

Answer 13

Conservative management by “drip and suck”: IV fluid resuscitation + NG tube to drain upper GIT
If signs of perforation, or no signs of improvement –> laparotomy

Question 14

What must all patients consent to, before being operated on for SBO?

Answer 14

• Possibility of an alternative patholgoy e.g. cancer
• Possibility of a stoma needing to be placed
• Ideally all of these patients should be counselled by a stoma therapist pre-op

Question 15

Causes of spontaneous small bowel perforation?

Answer 15

TB (HIV)
Typhoid (HIV)
Cytomegalovirus (HIV)
Malignancy
Crohn's disease
Steroids
Radiotherapy

Question 16

What is short bowel syndrome?

Answer 16

Patient presents with incapacitating diarrhoea, steatorrhoea and malnutrition following extensive small bowel resection
This is inevitable in patients with

Question 17

Management of small bowel syndrome?

Answer 17

Lifelong parenteral nutrition

Small bowel transplant is possible, but only practiced in the developed world

Question 18

What is Meckel’s diverticulum?

Answer 18

• True diverticulum
• Congenital malformation, vestigial remnant of the omphalomesenteric/vitelline duct
• Most common GIT malformation - 2% of people
• Usually located +-40cm from ileocaecal junction

Question 19

Complications of a Meckel’s diverticulum?

Answer 19

• Haemorrhage
• Obstruction
• Diverticulitis