Diarrhoea is defined as the loss of at least ___mls of fluid per day from the GI tract.
Which ion does water follow into GI cells?
Water moves into GI tract cells by ___.
Which transporter couples the influx of glucose and Na+ into enterocytes?
Apart from glucose, which other molecule is sodium ion influx coupled to?
Amino acid influx
Which types of GI tract infection can cause diarrhoea?
What is the most common bacterium causing diarrhoea in the UK?
Which bacterium most commonly causes Traveller's diarrhoea?
EnteroTOXIC E. coli
What non-infectious GI diseases can cause diarrhoea?
Why does hyperthyroidism cause diarrhoea?
What infection can the use of broad spectrum antibiotics cause?
leads to colitis, diarrhoea
Increased levels of which molecules lead to increased expression of channels causing increased secretion into the gut?
Toxins produced by infectious agents stimulate the enzyme ___ ___, which increase the levels of ____, which increases gut secretion causing diarrhoea.
adenylyl cyclase , cAMP/?cGMP
Diarrhoea can lead to ___ due to water loss.
Diarrhoea can lead to ___ ___ due to bicarbonate loss.
Diarrhoea can lead to ___ due to potassium loss.
Which disease, causing profuse watery diarrhoea, can be fatal if severe?
What is the first line therapy for severe diarrhoea?
Fluid replacement (oral/IV)
Is coupled glucose/Na absorption affected by diarrhoea?
No - this is why fluid replacement therapy works
Which channel is used in rehydration therapy?
Why is salt solution used in rehydration therapy?
Takes advantage of coupled glucose/Na transport through SGLT1
And then water follows Na, causing rehydration
What do oral rehydration fluids contain?
to take advantage of SGLT1 ⇒ rehydration
Why are antibiotics used in a limited role in managing diarrhoea?
Most infections are VIRAL (rotavirus, norovirus)
Most bacterial infections are self-limiting so what's the point in using antibiotics
Antibiotics are useful in (self-limiting / severe) diarrhoea.
Anti-motility agents (loperamide, opiates) are only used in (mild / severe) cases of diarrhoea.
you want the mucosa and toxins to be flushed out of the system - anti-motility agents slow this down
Opioids cause ___ by decreasing the rate of peristalsis and constricting sphincters.
Does the body develop a tolerance to the constipating effects of opioids?
What are some anti-motility agents used in diarrhoea?
Why is atropine added to the antimotility agent diphenoxylate?
Discourages abuse of diphenoxylate through side effects (nausea, headache, weakness, blurred vision)
What is constipation?
Production of hard stools requiring straining to pass
sense of incomplete defecation