Constipation & Diarrhoea: Causes & Management

Question 1

What is intestinal and colonic motility controlled by?

Answer 1

Primarily by Enteric nervous system, (Auerbach’s (myenteric) plexus and Meissner’s (submucosal) pleux

Question 2

What is the enteric nervous system?

Answer 2

has sensor and motor neurons, it doesnt need any input from the brain to work

Question 3

What is the haustra? (found in the large intestine)

Answer 3

Haustra are segemented pieces of the large intestine, controlled by pacemaker cells.

Question 4

What is the definition of constipation?

Answer 4

Frequency of bowel movements are less than three times a week,
Subjective (infrequent stools, diff cult stool passage, incomplete defecation, stools dry..

Question 5

what is primary and secondary constipation?

Answer 5

Primary: without known cause
Secondary: caused by medical condition or a drug (side effect)

Question 6

What is cause of primary constipation?

Answer 6

social factors
physical factors
psychological factors

Question 7

what is the cause of secondary constipation?

Answer 7

endocrine/metabolic diseases
systemic diseases 
myopathy
neurological disease 
Drug related

Question 8

What are the roles of endogenous opioid peptides in the receptors of the gut?

Answer 8

slow down the movement/ motility of the gut 
inhibit transmitter release, 
Inhibition of gastric emptying
affect peristalisis, 
affect the u receptors in the gut

Question 9

What do we use to manage chronic constipation?

Answer 9

LAXATIVES

Question 10

What are the four laxatives?

Answer 10

1. Bulk forming: increase the size and fluid content of stools
2. Stool softening: reduce surface tension and increase the fluid content of stools
3. Osmotic: increase the volume and retention of intraluminal fluids
4. Stimulant: increase peristalsis and water/electrolyte secretion by the mucous

Question 11

How do we manage opioid induced constipation?

Answer 11

Naloxegol (moventig)
doesnt cross the blood brain barrier, (so doesnt work on the brain)
It binds to opiod receptros in the myenteric and submucosal plexuses, blocks adverese actions on motility,

Question 12

What is the definition of diarrhoea?

Answer 12

The abnormal passage of loose or liquid stools more than three times daily and or a volume of stool greater 200g/day

Question 13

What are the 3 episodes diarrhoea?

Answer 13

Acute: lasting less than 14 days
Persistent: lasting longer than 14 days
Chronic: lasting more than 4 weeks

Question 14

What causes diarrhoea/

Answer 14

results from the excessive secretion and /or impaired absorption of fluid and electrolytes across the intestinal epithelium

Question 15

What are the four mechanisms of diarrhoea?

Answer 15

Osmotic
Secretory
Inflammatory
Abnormal Motility

Question 16

What is osmotic diarrhoea?

Answer 16

Excessive amounts of insoluble material in the lumen, water not reabsorbed.
this can be caused by ingestion of poorly absorbed susbstance or malabsorption e.g. lactose introlerance

Question 17

What is secretory diarrhoea?

Answer 17

abnormal ion transport, decrease in electrolyte absorption.
Excessive secretion and/or absorption across the intestinal epithelium
Exposure to toxin= prolonged opening of Calcium

Question 18

What is inflammatory Diarrhoea?

Answer 18

Mucosal destrution
Defective absorption of fluid and electrolytes, associated with both fluid and blood loss, caused by infection or disease

Question 19

What is abnormal motility

Answer 19

Increased motility leads to decreased absorption of fluid/electrolytes
A problem within the muscles that controls peristalsis, with the nerves or horomones that govern muscle contraction

Question 20

What are causes of Diarrhoea?

Answer 20

Viruses (rotavirus and small round structured virus)
Bacteria (including Campylobacter, E.coli, Salmonella
Antibitotics. usually the broad spectrum ones

Question 21

How does antibiotic cause Diarrhoea?

Answer 21

Alternation of normal intestinal flora

Loss of colonization resistance which leads to abnormal growth of pathogenic organisms i,e, C, diffcile, Cnandida

Question 22

How does antibiotic cause Diarrhoea?

Answer 22

Alternation of normal intestinal flora
Loss of colonization resistance which leads to abnormal growth of pathogenic organisms i,e, C, diffcile, Candida ablicans, Salmonella app…

Question 23

What are the treatment and management of diarrhoea?

Answer 23

Oral re-hydration solutions: prevents dehydration e.g. Diarolyte
Antimotility drugs, which increase bowel tone and delay intestinal transit time e.g. lopermide
Anti-secretory drugs, agents which reduce secretion e.g. bismuth subsalicylate