Diarrhoea Flashcards
What is diarrhoea?
Diarrhoea: too frequent evacuation of too fluid stools
How much extra water can create loose stools?
2% extra water can cause loose stools
How much water is excreted in stools daily?
Approximately 100ml of water is excreted in stools daily
What can diarrhoea be a side effect of?
Diarrhoea can be a side effect of drugs, therapy or disease
What percentage of water is reabsorbed in the small intestine?
90% of water is reabsorbed in the small intestine
How can diarrhoea have a protective role?
Diarrhoea can have a protective role by eliminating toxins that have been ingested
What are the symptoms of diarrhoea?
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
Name the 5 possible causes of diarrhoea (DPIFB)
5 possible causes of diarrhoea
*Diet
*Physiology
*IBS
*Food poisoning
*Bacteria
What are the two classifications of diarrhoea?
The two classifications of diarrhoea are acute and chronic
Describe acute diarrhoea
Acute diarrhoea:
*Happens suddenly
*Lasts 3 days or 1 to 2 weeks
*Self-limiting
*Resolves without sequelae
Describe chronic diarrhoea
Chronic diarrhoea:
*Lasts for more than 3-4 weeks
* Additional symptoms may present
What are the additional symptoms that may present in chronic diarrhoea?
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)
What are the 5 physiological causes of diarrhoea? IDOMS
5 physiological causes of diarrhoea:
* Inflammatory
* Deranged motility
* Osmotic
* Maldigestion
* Secretory
What stool volume/fluidity amount is considered to be excessive?
200ml or 200g of stool volume and fluidity is considered to be excessive.
Describe INFLAMMATORY diarrhoea
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.
Describe OSMOTIC diarrhoea
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
Systemic signs of inflammation
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.
Describe MALDIGESTION
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
Describe SECRETORY diarrhoea
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
Deranged motility
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)
Osmotic diarrhoea versus secretory diarrhoea
(Ways to categorise between the two)
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.
Stool osmolarity= serum osmolarity. What amount is usually in the body?
290-300 oSm Usually in body
Other causes of diarrhoea
-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
Diarrhoea Treatment
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
