Diarrhoea and Constipation Flashcards
How can we define diarrhoea?
It’s a symptom:
-Loose or watery stools
-More than 3 times a day
-Acute is less than 2 weeks
Describe the pathophysiology of diarrhoea
Physiological response to ingested toxins, infections and other irritants.
The body increases gut motility to flush the harmful substances out.
What are the 2 types of diarrhoea?
Osmotic
Secretory
When does osmotic diarrhoea occur?
Occurs when osmotically active substances (undigested molecules, poorly absorbed compounds) draw water into the gut.
Give an example of a condition that can cause osmotic diarrhoea
Lactose intolerance- insufficient lactase enzyme leads to osmotic effect of lactose on water
When does secretory diarrhoea occur?
When water and electrolytes are actively secreted into the gut lumen.
Often caused by bacterial infections, toxins or certain medications
What ion generates osmotic forces for water absorption in the GI tract?
Sodium ions
What type of diarrhoea leads to the largest increase in stool volume and why?
Secretory diarrhoea due to the active secretion of water into the gut
How can you alleviate osmotic diarrhoea?
Remove the substance causing it
E.g. avoiding lactose
This wouldn’t work with secretory diarrhoea
How do we define constipation?
Hard stools, difficulty passing stools or inability to pass stools.
What are some characteristics of constipation?
-Straining during >25% of defecations
-Lumpy or hard stools >25% of defecations
-Feeling of incomplete evacuation in >25% of defecations
-Feeling of obstruction or blockage to defecation in >25% of defecations
-Having fewer than three unassisted bowel movements a week
List 4 risk factors of constipation
-Female (x3 more than men)
-Certain medications
-Low level of physical activity
-Increasing age
How can constipation be classified?
Can be classified on transit types:
-normal transit
-slow colonic transit
-defecation problems
What are some causes of slow colonic transport?
-Large colon size: width of the bowel affects pressure exerted on stool for movement
-Fewer peristaltic movements
-Systemic disorders: MS, hypothyroidism, diabetes etc impact the nervous system
Give 5 treatments for constipation
Should treat underlying cause
-Physiological support for stress related constipation
-Increased fluid intake
-Enhanced physical activity
-Dietary fibre intake, fibre acts as osmotic force
-Laxatives
