Diarrhoea

Question 1

What is diarrhoea?

Answer 1

Diarrhoea: too frequent evacuation of too fluid stools

Question 2

How much extra water can create loose stools?

Answer 2

2% extra water can cause loose stools

Question 3

How much water is excreted in stools daily?

Answer 3

Approximately 100ml of water is excreted in stools daily

Question 4

What can diarrhoea be a side effect of?

Answer 4

Diarrhoea can be a side effect of drugs, therapy or disease

Question 5

What percentage of water is reabsorbed in the small intestine?

Answer 5

90% of water is reabsorbed in the small intestine

Question 6

How can diarrhoea have a protective role?

Answer 6

Diarrhoea can have a protective role by eliminating toxins that have been ingested

Question 7

What are the symptoms of diarrhoea?

Answer 7

Symptoms of diarrhoea:
* stools of excess volume and fluidity: 200ml or 200g a day
* increased frequency of defecation that deviates from the norm of the individual

Question 8

Name the 5 possible causes of diarrhoea (DPIFB)

Answer 8

5 possible causes of diarrhoea
*Diet
*Physiology
*IBS
*Food poisoning
*Bacteria

Question 9

What are the two classifications of diarrhoea?

Answer 9

The two classifications of diarrhoea are acute and chronic

Question 10

Describe acute diarrhoea

Answer 10

Acute diarrhoea:
*Happens suddenly
*Lasts 3 days or 1 to 2 weeks
*Self-limiting
*Resolves without sequelae

Question 11

Describe chronic diarrhoea

Answer 11

Chronic diarrhoea:
*Lasts for more than 3-4 weeks
* Additional symptoms may present

Question 12

What are the additional symptoms that may present in chronic diarrhoea?

Answer 12

Additional symptoms that may present in chronic diarrhoea are:
* weight loss
*frequent diarrhoeal stools
*fever
* anorexia
* chronic weakness
* nausea
* vomiting
* blood (may be extra cause for concern)

Question 13

What are the 5 physiological causes of diarrhoea? IDOMS

Answer 13

5 physiological causes of diarrhoea:
* Inflammatory
* Deranged motility
* Osmotic
* Maldigestion
* Secretory

Question 14

What stool volume/fluidity amount is considered to be excessive?

Answer 14

200ml or 200g of stool volume and fluidity is considered to be excessive.

Question 15

Describe INFLAMMATORY diarrhoea

Answer 15

Inflammatory diarrhoea:
* Due to enteritis (small intestine inflammation), IBDS, injury (ischaemia: blood flow/oxygen restricted to part of the body)
* Often involves fever and systemic signs of inflammation (if severe/invasive organism)
* Characterised by mucosal disruption and enterocyte damage.
* Rapid motility/abdominal cramps usually present. (Gut trying to remove irritant)
* Abnormal absorption of nutrients and electrolytes
* Low volumes of diarrhoea
* Mucus, blood and pus might be present.

Question 16

Describe OSMOTIC diarrhoea

Answer 16

Osmotic diarrhoea:
* Excess of non absorbable substances (e.g. lactose) min the lumen
* Non-absorbable substances cause an osmotic effect
* Water held in gut lumen

Question 17

Systemic signs of inflammation

Answer 17

Systemic signs of inflammation:
* Body pain, arthralgia, myalgia.
* Chronic fatigue and insomnia.
* Depression, anxiety and mood disorders.
* Gastrointestinal complications like constipation, diarrhea, and acid reflux.
* Weight gain or weight loss.
* Frequent infections.

Question 18

Describe MALDIGESTION

Answer 18

MALDIGESTION:
- Type of osmotic diarrhoea
- Inability to digest luminal contents: MALDIGESTION processes or malabsorption processes, Gut injury and surgery could affect absorption
- Undigested material causes osmotic diarrhoea
- Could be caused by Crohn’s

Question 19

Describe SECRETORY diarrhoea

Answer 19

SECRETORY diarrhoea:
-Abnormal ion transport in mucosal epithelium due to altered ion channel function.
- Leads to fluid secretion into lumen of gut.
- causative agents: bacterial toxins (CHOLERA), but also tumours, toxins, some foods and genetics

Question 20

Deranged motility

Answer 20

Deranged motility :
- Irregular muscle contractions or disruptions in normal coordination of movements in gut
- Caused by:
IBS, surgery (vagotomies), hormonal (hyperthyroidism), drugs (erythromycin) Altered motility affects GI function (digestion, absorption)

Question 21

Osmotic diarrhoea versus secretory diarrhoea
(Ways to categorise between the two)

Answer 21

Osmotic diarrhoea versus secretory diarrhoea
- Osmotic gap
Secretory diarrhoea < 50 mOsM/Kg
Osmotic diarrhoea > 100 mOsM/Kg

• Volume
  Secretory diarrhoea larger volume of plasma like fluid, contains large amount of electrolytes (ions not absorbed in gut/ increased secretion in lumen)

Secretory diarrhoea: generally responds poorly to diet changes.

Question 22

Stool osmolarity= serum osmolarity. What amount is usually in the body?

Answer 22

290-300 oSm Usually in body

Question 23

Other causes of diarrhoea

Answer 23

-Drugs!!!!
 Chemotherapy medicines
 Drugs used to treat heartburn and stomach ulcers  Immunosuppressants (such as mycophenolate)
 Nonsteroidal anti-inflammatory drugs (NSAIDs)
 Metformin used to treat diabetes
- Too much fibre: can stimulate peristalsis

Question 24

Diarrhoea Treatment

Answer 24

Diarrhoea:treatment:
- Change habits: avoid triggers
- Oral replacement therapy and rehydration are important
- Anti diarrhoea drugs:
Increase intestinal transit time (anti motility drugs)
Adsorbents
Inhibitors of secretion

Question 25

Diarrhoea compounds that inhibit secretion

Answer 25

1. Bismuth: reduces secretion by inhibiting pumps (Pepto-
   Bismol).
2. • Racecadotril (acetorphan): enzyme inhibitor*, reduces secretion of electrolytes and water into lumen

Question 26

Non specific treatment of diarrhoea: Oral Rehydration Therapy

Answer 26

Non specific treatment of diarrhoea: Oral Rehydration Therapy
Rehydration salts.
First aid!
Simple concept, v. Cheap, huge impact.
– glucose/salt solution – stimulates SGLT1 (water will follow)

Question 27

Antimotility drugs:Opiates

Answer 27

Antimotility drugs: Opiates
- Loperamide (Imodium)
 Selective action on GI tract
-Binds to opioid receptor of enteric nervous system, hyper polarises enteric neurons, downregulates peristalsis
 No CNS effects: can’t cross the blood brain barrier. Won’t cause addiction
 First choice anti diarrhoeal
NOTE: Not for use in bloody and pus containing diarrhoea
Others? • Codeine : could cause addiction
These drugs have CNS effects which limits their use in the clinic