Diarrhoea Flashcards
what is diarrhoea?
A symptom that occurs in most conditions
- loose/ watery stool
- more than 3 times a day
- acute diarrhoea (less than 2 weeks)
what is the pathophysiology behind diarrhoea
- unwanted substance stimulates secretion from epithelial cells
- colon can’t absorb all the water
how is water moved across the gut?
via transcellular and paracellular
follows osmotic forces by movement of electrolytes and nutrients (Na)
what is osmotic diarrhoea?
- water drawn into gut
- high osmotic pressure
- due to not being able to absorb molecules in gut
- stool volume will be moderately increased
- if you stop eating then it reduces
what is secretory diarrhoea
- due to an infection
- water is actively secreted into gut
- epithelial cells are trying to flush out the infection
- dies not reduce when food consumption is reduced
how does CFTR cause more water to be pumped out?
- toxin or virus inside the cell
- increases CAMP
- causes the CFTR to pump out more Cl
- this causes the movement of Na ions moving paracellular
- this causes water to follow
how can a lack of lactase enzyme cause diarrhoea?
lactose can’t be broken down
it accumulates inside the gut
water is drawn into the colon
this will settle if you stop ingesting lactose
what are some reasons of diarrhoea?
- too little absorption of sodium ( where sodium goes water goes) so it will stay in the gut
due to: - bowel resection -> reduced surface area
- inflamed surface -> wont do job properly
- intestinal rush -> no contact time for nutrients to be absorbed
what is constipation?
- difficulty to pass stool
- lumpy/hard stool
- feeling of incomplete evacuation
-feeling of obstruction or blockage
what are some risk factors of constipation
- female (x3 male)
-certain meds - low physical activity
- increasing age and also very young kids
what are the three main reasons for constipation?
- normal transit constipation
-slow colonic transport
-defaecation problems
what are the reasons for slow transit constipation
psychological stressors
what are reasons for slow colonic transporters
- large colon
- slow transport so more water will be reabsorbed and stool will be hard
-large distended colon slowers transport - fewer pacemakers so fewer peristaltic movements
- nervous system disease
how do defection problems arise
- can’t coordinate muscles of defecation
- problems in pelvis / pelvic floor
what is some treatment for constipation
-psycological support
-increased fluid intake
-increased activity
-increased dietary fibre
-laxatives
this is an X-ray image of a build up if stool
what is appendicitis?
- inflammation of appendix
- appendix is a diverticulum of caecum
- it has a separate blood supply to the caecum from ilecolic branch of SMA
why is the location of the appendix important
- different postions have different presentations
what is acute appendicitis
acute: inside starts to swell and inflammation can lead to outside and cause necrosis and can perforate the appendix
can lead to peritonitis -> all the intense of the appendix has now entered the bowel
what is the main cause for appendicitis
- something that blocks the entrance of the appendix
- will cause a high pressure in appendix
- venous pressure rises
- arteriole blood wont be able to enter
- you get ischemia
- faecolith can block (hard stool)
- lymphoid hyperplasia: lymphoid tissue enlarges due to recent infection and blocks the entrance
- a foreign body can block off the appendix
what is the classic presentation of appendicitis
- poorly localised peri umbilical pain
- so painful => anorexia don’t want to eat
- nausea
-low grade fever
why do you get poor localised pain with appendicitis?
- appendix is an intraperitoneal structure
- visceral afferents are stimulated
- pain is referred to T10,9
- appendix is inflamed and can touch parietal peritoneum
what type of pain do do you get with appendicitis when the appendix is recto -caecal or pelvic
- wont get right iliac fossa pain like normal
- supra pubic pain, right sided rectal or vaginal pain
what are two cases where appendicitis is hard to diagnose
- children
- pregnant women
what are signs that a patient has appendicitis
- slightly ill
- still (painful to move)
- localised right quadrant tenderness
- rebound tenderness in right iliac fossa