Diarrhoea And Constipation

Question 1

What is Diarrhoea?

Answer 1

Loose or watery stools where you go more frequently (>3times per day)

Question 2

What is acute diarrhoea?

Answer 2

Diarrhoea lasting less than 2 weeks

Question 3

What is the pathophysiology of acute diarrhoea?

Answer 3

Unwanted substances in the gut stimulates secretion and motility of gut to get rid of it

Question 4

What are the 2 main causes for diarrhoea?

Answer 4

Increased epithelial secretion (MOST COMMON)

Increased gut motility (decreases contact time/time for absorption)

Question 5

What are the 2 types of diarrhoea?

Answer 5

Osmotic diarrhoea
Secretory diarrhoea

Question 6

What is osmotic diarrhoea?

Answer 6

When theres an increased amount of osmotically active particles in the gut lumen so more water is draw into the lumen

Question 7

How is osmotic diarrhoea affected when the patient fasts?

Answer 7

Diarrhoea stops since stopping the intake of the osmotically active particles

Question 8

What is secretory diarrhoea?

Answer 8

When the epithelium of the gut secretes lots of Cl- ions

Question 9

What ion channel is often affected causing secretory diarrhoea?

Answer 9

CFTR

Due to a toxin, virus, med or serotonin increasing its expression so more Cl- in lumen so more Na+ follows and more water follows

Question 10

What are some causes of osmotic diarrhoea?

Answer 10

Ingesting material that is poorly absorbed (anatacids like magnesium sulphate)

Inability to absorb nutrients like lactose in lactose intolerance

Will stop if you stop injesting offending substance

Question 11

What are some causes of osmotic diarrhoea where there’s too little absorption of Sodium (Na+)?

Answer 11

Reduced SA for absorption (bowel removal)
Mucosal disease like coeliacs or inflammatory bowel disease (Chron’s)

Reduced contact time (intestinal rush/inc peristalsis) caused by Diabetes or IBS

Question 12

What is constipation?

Answer 12

When stools are hard, difficult to pass or you’re unable to pass stools or theres incomplete evacuation of the bowel

Question 13

What are the risk factors for constipation?

Answer 13

Femal
Certain medications (opioids and anti diarrhoea)
Physical inactivity
Age

Question 14

What are the 3 ways constipation can happen?

Answer 14

Slow colonic transport
Defaecation problems
Normal transit constipation (other related stressors)

Question 15

How does slow colonic transport cause constipation?

Answer 15

Increased contact time so more water reabsorbed from stool

Question 16

What can cause slow colonic transport?

Answer 16

Large/wide colon
Fewer peristalsic motions
Fewer intestinal pacemaker cells (Hirschprungs disease)
Systemic disorders (hypothyroidism and diabetes)
NS disease (Parkinson’s , MS)

Question 17

What is meant by defaecation problems?

Answer 17

Unable to coordinate muscles of defaecation

Question 18

How do you treat constipation?

Answer 18

Depends on cause:
Psychological support if psychological stressor
Inc fluid intake if dehydrateeed
Inc activity if immobile
Inc dietary fibre (inc osmotic particles in lumen)
Fibre meds
Laxative

Question 19

How do laxatives work?

Answer 19

Are kind of what causes diarrhoea:

Osmotic laxatives (magnesium sulphate + diasaccharides) stay in lumen (LACTULOSE)
Stimulatory laxatives (Chloride channel activators (secretory diarrhoea) (senna)
Stool softeners (arachis oil enema)