Diarrhoea Flashcards
What is the definition of diarrhoea?
A change in normal bowel habit resulting in increased frequency of bowel movements and the passage of soft or watery stools.
May be accompanied by colicky pain due to increased contraction of smooth muscle and additional production of gas which can cause discomfort.
Its a SYMPTOM not a disease
What is acute diarrhoea?
Abrupt onset of >3 loose stools a day and lasts no longer that 14 days
Can have dietary causes e.g. alcohol or spicy foods
Can be a bacterial or viral infection
Majority resolve within 2-3 days without specific treatment
What is chronic diarrhoea?
Pathological cause
Lasts over 14 days
Possibly flare up of previously diagnosed condition e.g. IBS
Needs further investigation to identify the underlying the cause.
What are the morbidity factors for diarrhoea?
Age and nutritional status are most important host factors in determining severity and duration
The younger the child, the higher risk for severe, life-threatening dehydration as their immune system is not as strong and they can’t physically consume enough water to rehydrate themselves.
What is the pathophysiology of diarrhoea?
Essentially the change in balance between the absorption and secretion of water and electrolytes.
It can be due to 2 reasons:
- An osmotic force that drives water into the gut lumen, e.g. after ingestion of non absorbable sugars
- Proportional to the intake and responsive to fasting - meaning if the patient is un able to digest a certain type of sugar, then more severe symptoms would occur, hence if they stop consuming that sugar they’re condition will better.
OR 2. Enterocytes (cells lining the GI tract) actively secreting fluid e.g. enterotoxin-induced diarrhoea
- Not responsive to fasting (so even if they avoid that substance it will make no difference as its caused by a pathogen)
- Ion transporters are activated by the bacteria by e.g. bacteria resulting in pathogens:
-> Invading enterocytes or
-> Producing enterotoxins which damage cells or
-> Inducing cytokine secretion to produce prostaglandins which stimulate secretion (hence extra secretion of fluids and electrolytes promoting the loss of water through diarrhoea)
What is the mechanism of how bacteria can cause bacteria?
- Invasive mechanism:
- Specific types of microorganism can directly attach mucosal cells which causes diarrhoea
- Stools may contain blood and pus
- Develop a fever
- E.g. Shigella, Salmonella, Yersinia, Enteroinvasive E Coli
- Non-invasive mechanism:
- They do not directly damage the gut
- But the bacteria produce enterotoxins that disrupt secretion
- Watery diarrhoea
- E.g. S aureus, B cereus, C perfinngens, Enterotoxigenic E coli
How do we diagnose diarrhoea? What factors do we look at?
- Symptoms
- Any associated symptoms? e.g. temp, fever, blood etc
- How quickly was the onset?
- Is there an absence of stool formation? - Trigger factors?
- “Bad”/unusual food, alcohol, drugs, contaminated water etc - Time/intensity
- Dehydration in major risk groups
- How long and severe are the symptoms - Fecal studies
- To identify the pathogen - Serum albumin (to identify if theres any loss of protein hence suggesting theres damage taking place in the GI tract)
- Fecal alpha 1 antitrypsin (to identify if theres any loss of protein hence suggesting theres damage taking place in the GI tract)
- Intestinal biopsy (VERY SEVERE CASES)
What is gastroenteritis?
Inflammation of the stomach and intestines, typically resulting from bacterial toxins or viral infections causing vomiting and diarrhoea.
What are the common causes of diarrhoea in infants?
- Infectious gastroenteritis
- Toddlers diarrhoea
- Food intolerance
- Coeliac disease
What are the common causes of diarrhoea in school age children?
- Infectious gastroenteritis
- Drugs (Antibiotics)
What are the common causes of diarrhoea in adults?
- Infectious gastroenteritis
- IBS
- IBD
- Drugs
- Excess alcohol
- Spicy food
- Coeliac disease
What are the common causes of diarrhoea in older people (elderly)?
- Infectious gastroenteritis
- Large bowel cancer
- Faecal impaction
- Drugs
- Ischaemic colitis
How can we prevent diarrhoea?
Good hygiene: Wash hands regularly
- After visiting the toilet
- Before touching food
- After gardening
- After playing with pets
- Between handling raw and cooked food
What are the treatment aims of treating acute diarrhoea in adults?
- Prevention and reversal of fluid and electrolyte depletion
- Management of dehydration (if present)
- Most acute diarrhoea settle spontaneously (at around 3 days)
- Oral rehydration therapy provided if needed
For rapid control of symptoms:
LOPERAMIDE:
Prescribed dose > 12 years: Initially 4mg, followed by 2mg after each loose stool (for up to 5 days max); Usual dose 6-8mg daily ; maximum 16mg per day (8 caps)
GSL/P dose > 12 years: Initially 4mg followed by 2mg after each loose stool (for up to 48hrs max); usual dose 6-8mg daily; maximum 12mg per day (6 caps)
- We get the patient to eat as soon as possible/able (bland) - soups, bread, pasta, rice, potatoes
- Avoid caffeine, alcohol, carbonated drinks (diuretics)
Why should anti-motility drugs be avoided in severe gastroenteritis or dysentery?
As these conditions are more serious - consisting of blood/music In stools and fever
The concern is that Loperamide can prolong the infection.
- Prevention and treatment of fluid and electrolyte depletion is primary importance - Oral rehydration therapy*
