Intestinal Obstruction and Tumours

Question 1

What are the 3 main causes of intestinal obstruction?

Answer 1

1) Contraction
2) Increased pressure
3) Blockage

Question 2

What are 3 causes of blockage?

Answer 2

1) Tumour
2) Diaphragm disease (NSAIDs)
3) Gallstones in bladder (rare)

Question 3

What are 3 causes of contraction?

Answer 3

1) Hirschsprung’s disease
2) Inflammation
3) Intramural Tumours

Question 4

How is intestinal obstruction caused by Crohn’s disease?

Answer 4

1) Crohn’s disease –> Inflammation –> Fibrosis –> Contraction –> Obstruction

Question 5

How does Diverticulitis cause the intestinal obstruction?

Answer 5

Outpouching of the mucosa, leads to faecal matter being trapped, inflammation in bowel wall, contraction leads to obstruction

Question 6

What is Hirschsprung’s disease?

Answer 6

Congenital condition of lack of motility in the Bowel from lack of nerves, causing obstruction and gross dilation

Question 7

What are 3 causes of pressure?

Answer 7

1) Volvulus
2) Adhesions
3) Peritoneal Tumour

Question 8

What is a Volvulus and where will it most likely be seen?

Answer 8

Closed loop obstruction from twist/rotation in the Bowel, presenting a risk of necrosis
- Free floating sections of the bowel, e.g. mesentery –> Sigmoid colonic is long so can twist in on itself

Question 9

Define and describe the causes of Adhesions

Answer 9

Def: Stuck together loops of bowel which distort and pull the bowel (Sec to surgery)
Desc: Secondary effect after abdominal surgery

Question 10

What are 4 common adult causes of small bowel obstruction?

Answer 10

1. Adhesions.
2. Hernias.
3. Crohn’s disease.
4. Malignancy.

Question 11

What are 3 common child causes of small bowel obstruction?

Answer 11

1. Appendicitis.
2. Volvulus.
3. Intussusception.

Question 12

Which type of Bowel obstruction is more common?

Answer 12

Small Bowel (Makes up 75%)

Question 13

What is intussusception?

Answer 13

Part of the intestine invaginates into another section of the intestine -> telescoping. It is caused by force in-balances.

Question 14

What is a Hernia?

Answer 14

Protrusion of part of the viscera into cavity into an area where doesn’t belong

Question 15

What is the main risk of an untreated Hernia? What are the main symptoms?

Answer 15

Irreducible: Can’t return them to correct body cavity as can become strangulated
1) Palpable Lump 2) Abdominal pain

Question 16

Would dilatation, distension and increased secretions be seen proximal or distal to an intestinal obstruction?

Answer 16

Proximal

Question 17

What are main 5 symptoms of small bowel obstruction?

Answer 17

1. Vomiting.
2. Pain.
3. Constipation.
4. Distension.
5. Tenderness.

Question 18

What are main signs of small bowel obstruction?

Answer 18

1) Increased vital signs
2) Resonance
3) Tenderness and Swelling
4) Bowel sounds

Question 19

What investigations would be done for small bowel obstruction?

Answer 19

1) Good Patient History
2) X-Ray
3) MRI, CT scan Ultrasound
4) FBC, U&E, and Lactate

Question 20

What is the main management and treatment for SBO?

Answer 20

1. Fluid resuscitation.
2. Bowel decompression.
3. Analgesia and anti-emetics.
4. Antibiotics.
5. Surgery e.g. laparotomy, bypass segment, resection.

Question 21

What are the main causes and symptoms of LBO?

Answer 21

C: Volvulus, Colorectal Cancer
S: Tenesmus, Constipation, Bloating, Vomit, Weight Loss, Abdominal Discomfort

Question 22

What are the investigations and treatments for LBO?

Answer 22

I: DRE, Sigmoidoscopy, Plain X-Ray, CT
T: Fast patient, supplementary O2, IV fluids to replace losses and correct electrolyte, urinary catheterisation to monitor urinary output

Question 23

What are the 3 main causes of untreated intestinal obstructions?

Answer 23

1) Ischaemia
2) Necrosis
3) Perforation

Question 24

How does normal epithelium progress to colorectal cancer?

Answer 24

1) Normal epithelium
2) Adenoma
3) Colorectal adenocarcinoma
4) Metastatic adenocarcinoma

Question 25

What is an adenocarcinoma?

Answer 25

Malignant tumour of glandular epithelium

Question 26

What is familial adenomatous polyposis?

What is its PP?

Answer 26

C: Genetic condition causing development of thousands of polyps during teen years
PP: Mutation in APC protein, so apc/GSK complex isn’t formed and beta catenin levels increase, causing up-regulation of adenomatous gene transcription

Question 27

How can adenoma formation be prevented?

Answer 27

NSAIDs

Question 28

What is HNPCC and the treatment for it?

Answer 28

HNPCC: Inherited higher tendency to develop colorectal cancer
T: No DNA repair proteins so risk of colonic and EM cancers

Question 29

What is the treatment for colorectal adenocarcinoma?

Answer 29

Surgical resection can be done when there is no spread. Remember to balance risks v benefits. The patient has a pre-op assessment.
If metastatic: Chemotherapy & Palliative Care

Question 30

Why has Bowel Cancer survival increased and what are the main risk factors?

Answer 30

Increased: Colonoscopic Technique, Screening Programme, Treatment Options better
RF: Alcohol, Smoking, Diet: Low fibre or High red meat, PMH of adenoma/ulcerative colitis, family history of CC
(Presentation affected by proximity to rectum)

Question 31

What are main signs of rectal cancer?

Answer 31

1. PR bleeding.
2. Mucus.
3. Thin stools.
4. Tenesmus.

Question 32

What are the signs of Left and Right side sigmoid cancer?

Answer 32

L: PR Bleeding, Change of Bowel Habit
R: Anaemia, Mass and non-settling Diarrhoea

Question 33

What investigations might you do in someone who you suspect might have colorectal cancer?

Answer 33

Colonoscopy = gold standard!
It permits biopsy and removal of small polyps.
- Tumour markers are good for monitoring progress.
- Faecal occult blood is used in screening but not diagnosis.

Question 34

What are the emergency presentations of each type of cancer?

Answer 34

LHS: Narrow and most likely to show signs of obstruction
RHS: Signs of perforation as RHS is wide