Small bowel obstruction

Question 1

List some causes for a small bowel obstruction

Answer 1

Adhesion
Hernia
Cancer- small bowel cancers are extremely rare, but external cancers could trap a loop of small intestine

Question 2

What are adhesions?

Answer 2

External compression of the small intestine.

The patient has usually had previous abdominal surgery and an adhesion is the abdominal response to healing.

Question 3

What abdominal hernias are most common, and how do they cause a small bowel obstruction?

Answer 3

Inguinal, femoral, incisional and umbilica.
These all have the ability to attract and trap a loop of small bowel.
This happens because they offer a pathway of low resistance, so the bowel insinuates its way into the hernia and gets stuck there.

Question 4

How does a small bowel obstruction present?

Answer 4

Colicky pain
Other symptoms are determined by where the obstruction is:
proximal- vomiting, no distension
distal- late vomiting, gross distension

Question 5

How is small bowel obstruction diagnosed?

Answer 5

History
Examination
Plain abdominal X ray

Question 6

What is the difference between large and small bowel colic?

Answer 6

In the small bowel, colicky pain occurs every 10 minutes or so, whereas in the large bowel it occurs 2 or 3 times an hour.

Question 7

How can a small bowel obstruction be told apart from a large bowel obstruction on an X ray?

Answer 7

On an X ray, the distended loops of a large bowel obstruction would be around the outside of the abdomen.
The distended loops of a small bowel obstruction are in the centre of the abdomen.

Question 8

What is the treatment of a small bowel obstruction if there is no strangulation?

Answer 8

IV fluids
Nasogastric suction
Operate if no resolution in 24-48 hours

Question 9

What is strangulation of the bowel?

How does the patient present?

Answer 9

This is the point beyond ischaemia.
If there is an ischaemic bit of intestine and the blood supply isn’t restored, the bowel will become gangrenous. When this is due to an obstruction this is called strangulation.
The patient has constant pain (not colicky), shock, and the three Fs of sepsis: fever, flush, fast pulse

Question 10

What is the treatment of small bowel obstruction with strangulation?

Answer 10

Resuscitate
Antibiotics
Early surgery

Question 11

How is Crohn’s disease diagnosed?

Answer 11

Barium follow through/enema

Gastroscopy/colonscopy

Question 12

What are clinical features of small bowel ischaemia and infarction?

Answer 12

Severe, poorly localised pain
Sepsis
Shock

Question 13

Who tends to get small bowel ischaemia and infarction?

Answer 13

Elderly patients

Arteriopaths

Question 14

Why is small bowel ischaemia sometimes confused with pancreatitis?

Answer 14

There is a small rise in amylase in small bowel ischaemia/infarction, and this is also present in pancreatitis.

Question 15

What is the treatment for small bowel ischaemia/infarction?

Answer 15

Revascularise the intestine

Resect gangrenous intestine

Question 16

What is abdominal angina?

Answer 16

Post prandial pain

Due to Poor blood supply to the intestine

Question 17

What is Meckel’s diverticulum?

Answer 17

A diverticulum that consists of all three layers of the intestinal wall (unlike in diverticular disease where it is just the mucosa and submucosa).
It is a remnant of vitello intestinal duct

Question 18

What age group is affected by Meckel’s diverticulum?

Answer 18

Children

Question 19

What are the symptoms of Meckel’s diverticulum?

Answer 19

Rectal bleeding
Obstruction
perforation
It can be an asymptomatic finding in adults

Question 20

What is the 2/2/2 rule in Meckel’s diverticulum?

Answer 20

It is 2 inches long
It is 2 feet from the terminal ileum colon junction
It is found in 2 percent of people

Question 21

What causes the rectal bleeding in Meckel’s diverticulum?

Answer 21

There can be ectopic gastric mucosa which can secrete acid. This can erode the lining of the small intestine, causing rectal bleeding.

Question 22

What causes the obstruction in Meckel’s diverticulum?

Answer 22

Sometimes a fibrous band exists between the diverticulum and the umbilicus. The child then develops obstruction secondary to this congenital adhesion.

Question 23

What is a Technicium Tc 99M scan used to detect?

Answer 23

To detect gastric mucosa

Question 24

Name one very common and one very rare disease of the appendix.

Answer 24

Common: acute appendicitis
Rare: Carcinoid tumour of the appendix

Question 25

What are the clinical features of acute appendicitis?

Answer 25

Ill defined initial symptoms- visceral epigastric pain
Nausea and anorrhexia
These progress to Right iliac fossa pain and peritonism

Question 26

What anatomical factors can contribute to atypical appendicitis?

Answer 26

The position of the appendix

The position of the caecum

Question 27

What is the treatment for appendicitis?

Answer 27

Laparoscopy and laparascopic appendicectomy
or
Laparoscopy and open appendicectomy

Question 28

What are the clinical features of carcinoid tumour of the appendix?

Answer 28

It is an asymptomatic finding
It is a brown-yellow nodule
They can be at the tip or the base of the appendix
Larger tumours and those at the base can produce metastases

Question 29

How are carcinoid tumours of the appendix removed?

Answer 29

If they are at the tip: appendicectomy

If they are the base: Right hemicolectomy

Question 30

What is the effect of liver metastases from the carcinoid tumour of the appendix?
Why does this effect not happen without metastases?

Answer 30

Carcinoid syndrome:
the carcinoid deposits secrete vasoactive amines
there is facial flushing and diarrhoea.

The original carcinoid tumour can also secrete these, but they are secreted into the portal venous system and metabolised in the liver.
If there is metastasis to the liver, the vasoactive amines are secreted into the systemic circulation.