Distal GI Tract Pathology

Question 1

What is diarrhoea?

Answer 1

Loose or water stools

>3 times a day

Question 2

What is the pathophysiology of diarrhoea?

Answer 2

Unwanted substance in gut - stimulates secretion + motility

Colon unable to remove water - loose stool

Question 3

What are the types of diarrhoea?

Answer 3

Secretory

Osmotic

Question 4

What is secretory diarrhoea?

Answer 4

Messed up electrolyte transport

Question 5

What are the 2 mechanisms of secretory diarrhoea?

Answer 5

Too much secretion of ions

• infection affects messenger system
• net secretion of Cl- or HCO3-

Too little sodium absorption

• reduced surface area for absorption
• water follows sodium

Question 6

What is osmotic diarrhoea?

Answer 6

Gut lumen contains too much osmotic material

Question 7

What causes osmotic diarrhoea?

Answer 7

Ingesting material that is poorly absorbed

Inability to absorb nutrients

Question 8

What is constipation?

Answer 8

Hard stools

Difficulty passing stools

Question 9

What is the pathophysiology of constipation?

Answer 9

Slow colonic transport
Fewer peritstalitc movements
More water absorbed

Question 10

How is constipation managed?

Answer 10

Increased fluid intake
Increased activity
Increased dietary fibre
Laxatives

Question 11

What is appendicitis?

Answer 11

Inflammation of appendix

Question 12

What is the appendix?

Answer 12

Diverticulum off of the caecum

Question 13

What is the blood supply of the appendix?

Answer 13

Ileo-colic branch of the SMA

Question 14

What are the different lies of the appendix?

Answer 14

Retro-caecal 
Pelvic
Sub-caecal 
Para-ileal 
Para-caecal

Question 15

What causes appendicitis?

Answer 15

Blockage of the appendix lumen - usually faecolith increases pressure in appendix

Venous pressure rises = oedema

Reduction in arterial supply

Ischaemia

Bacterial invasion

Question 16

What are the symptoms of appendicitis?

Answer 16

Pain - umbical -> RIF
Anorexia
Nausea
Low grade fever

Question 17

What are the signs of appendicitis?

Answer 17

Low grade fever
Tachycardia
RIF tenderness
Rebound tenderness in McBurney’s point

Question 18

Where is McBurney’s point?

Answer 18

2/3 of the way from umbilicus to ASIS

Question 19

What is diverticulosis?

Answer 19

Outpouchings of mucosa and submucosa that herniate through muscularis layers

Question 20

What is acute diverticulitis?

Answer 20

When diverticula become inflamed or perforate

Question 21

What is the pathophysiology of acute diverticulitis?

Answer 21

Entrance to diverticula blocked by faceses

Inflammation + bacterial invasion

Question 22

What are symptoms of acute diverticulitis?

Answer 22

Abdominal pain
Fever
Bloating
Constipation

Question 23

How is acute diverticulitis managed?

Answer 23

Antibiotics
Fluids
Analgesia

Question 24

What are haemorrhoids?

Answer 24

Symptomatic enlarged anal cushions

Question 25

What are the types of haemorrhoids?

Answer 25

Internal haemorrhoids

External haemorrhoids

Question 26

What are internal haemorrhoids?

Answer 26

Haemorrhoids formed above dentate line that enlarge and prolapse through anal canal

Question 27

What are the symptoms of internal haemorrhoids?

Answer 27

Relatively painless
Bright red blood
Pruritus

Question 28

What are external haemorrhoids?

Answer 28

Swelling of anal cushions below dentate line which may then thrombose

Question 29

What is an anal fissure?

Answer 29

Linear tear in the anoderm

Causes pain on defecaetion

Question 30

What is haematochezia?

Answer 30

Passage of bright red blood through stools

Question 31

What causes haematochezia?

Answer 31

Diverticulitis
Angiodysplasia
Colitis 
Colorectal cancer 
Anorectal disease