Approach to Diarrhoeal illness Flashcards
acute diarrhoea
<14 days
persistent diarrhoea
more than 14 days
chronic diarrhoea
more than 30 days
blood tests
haemoglobin
urea and creatinine
electrolytes - sodium, K, magnesium
CRP
iron stores
causes of acute infectious watery diarrhoea
norovirus
rotavirus
campylobacter spp.
eschericia coli
causes of acute infectious inflammatory diarrhoea
clostridium deficile
escherichia coli
shigella spp.
positive stool sample
stool samples are only positive in 1-5% of cases
diarrhoea in pregnant women
listeria monocytogenes?
developed symptoms within six hours
performed toxins - staph aureus?
reheated rice
bacillus cereus
post ingestion of pork products
yersinia spp. (usually a few days incubation)
recent antibiotic therapy or hospitalisation
clostridium difficile
acute diarrhoea mananegemtn
most cases are self limiting and do not require antibiotics
fluid and electrolyte replacement
consider antibiotics if:
severe disease
immunosuppressed
significant comorbidities
anti diarrhoeals
not recommended as first line therapy
acute diarrhoea oral rehydration solutions (ORS)
SGLT-1 protein usually unaffected
relies on cotransport of sodium and glucose
pulls water into vascular system
low osmolarity solution recommended
what to test for in persistant diarrhoea
reasonable to test for parasitic organisms if not already done
often need to specifically request ‘ova and parasite’ exam
types of parasites that might be the cause of persistent diarrhoea
giardia (lol sam)
cryptosporidium
entamoeba histolytica
often associated with travel
causes of chronic diarrhoea
resource limited places: chronic bacterial Orr parasitic infections
resource rich areas: functional disorders, inflammatory bowel disease, malabsorption syndromes
nature of secretory chronic diarrhoea
watery, voluminous bowel movements, often with nocturnal symptoms and a lack of response to fasting
patients often have electrolyte disturbances and dehydration
nature of secretory chronic diarrhoea
watery, voluminous bowel movements, often with nocturnal symptoms and a lack of response to fasting
patients often have electrolyte disturbances and dehydration
may be caused by medications such as lactulose, laxatives, magnesium supplements or ingestion of alcohol sugars (sorbitol, mannitol, xytol)
nature of malabsorbtive chronic diarrhoea
the lack of uptake of luminal contents
coeliac disease, pancreatic insufficiency
small intestinal bacterial overgrowth which is associated with a variety of diseases eg. systemic sclerosis, diabetes, cirrhosis and portal hypertension, strictures, previous surgeries etc.
nature of inflammatory chronic diarrhoea
not just IBD
microscopic colitis is divided into two subgroups
- lymphocytic colitis with has a lymphocyte predominant infiltrate
- collagenous colitis also features a sub epithelial collagen band
chronic inflammation in both leads to epithelial destruction
eosinophilic enteritis can be associated with other conditions like EO or atopic conditions. patients may need steroid therapy
appropriate investigations for chronic diarrhoea
bloods for electrolytes, serum albumin and nutrient deficiencies
measurement of stool sodium osmotic gap
faecal elastase
faecal calprotectin to evaluate for IBD
faecal fat measurement is rarely done
gastroscopy and colonoscopy
coeliac disease
an immune mediated enteropathy against dietary gluten
patients with coeliac disease generate antibodies against
gliadin (which makes up gluten) and to tissue transglutaminase
what happens after ingestion of gluten in coeliac people
mucosal immune response
1. increased intraepithelial lymphocytes
2. villous atrophy
3. crypt hyperplasia
diagnosis of coeliac disease
sensitivity and specificity of the anti-TTG antibody assay is very high
duodenal biopsy remains gold standard because you can evaluate the severity of mucosal changes
symptoms of coeliac disease
can be very non-specific
diarrhoea
abdo pain and bloating
unexplained iron deficiency
neurological symptoms
dermatitis herpetiformis
coeliac disease management
lifelong adherence to a strict gluten free diet
replace nutrient deficiencies
prevention of bone loss
vaccination
monitoring for refractory disease and complications
churns disease
a chronic inflammatory disease of the GI that can affect any part from mouth to anus
most typically characterised by transmural inflammation
ulcerative colitis
a chronic inflammation disease of the colon that starts in the rectum and can extend proximally to involve all segments of the colon
most typically characterised by mucosal inflammation only
pathogenesis of IBD
genetics
environment - smoking, emulsifiers
microbiome - loss of diversity
barrier defects - bacteria more easily more across the gut wall causing inflammation
innate and adaptive immune dysfunction - immune cells become less tolerant and produce more pro inflammatory cells
clinical features of chrons disease
diarrhoea for more than 6 weeks
abdo pain
weight loss
perianal fistulas
systemic symptoms including malaise, anorexia, feverr
clinical features of ulcerative colitis
blood in stools
rectal urgency
tenesmus
mucous in stools
nocturnal defecation
crampy abdo pain
left iliac fossa pain
which IBD disease has fistulas
chrons
which IBD disease has skip lesions
chrons
which IBD disease affects colon only
ulcerative colitis
chrons is anywhere from mouth to anus
which IBD disease has bloody diarrhoea
both but chrons is often non-bloody
thickness of mucosal damage in IBD diseases
UC - involves the lining (mucosa) only
chrons - transmural
impact of smoking on development of IBD disease
chrons - higher risk
UC - lower risk
which IBD disease has cobblestone mucosa on colonoscopy
chrons
medical therapies for IBD
steroids
immunomodular drugs
biologic drugs (infliximab, adalimumab, vedolizumab, ustekinumab)
surgical therapies for IBD
limited small bowel resections in churn’s disease
colectomy for severe ulcerative colitis with restorative pouch
perianal abscess drainages and fistulotomy
irritable bowel syndrome
chronically recurring abdo pain or discomfort and altered bowel habits
often co-exists with depression and anxiety and involves significant impairment to quality of life
symptoms of irritable bowel syndrome
abdo pain
bloating
excess flatulence
diarrhoea
constipation
things that are not features of IBS
bloody stools
weight loss
fever
signs of systemic inflammation
subtypes of irritable bowel syndrome
IBS-C: constipation predominant
IBS-D: diarrhoea predominant
IBS-M: mixed type
IBS-U: undefined
IBS syndrome management
largely lifestyle based
low FODMAP diet for diarrhoea predominant symptoms
laxative and increased soluble fibre for constipation dominant symptoms
anti-spasmodics
CBT
