Diarrhea acute/chronic Flashcards
define diarrhea
passage of abnormally liquid or unformed stools at an increased frequency
define acute, persistent and chronic diarrhea
acute: lasting less than 2 weeks
persistent: 2-4 weeks
chronic: above 4 weeks in duration
* must distinguish between frequent passage of small volumes of stool often associated with rectal urgency and fecal incontinence (involuntary discharge of rectal contents)
what causes most cases of acute diarrhea
90% are caused by infectious agents
remaining 10% caused by toxic ingestions, ischemia and medications
list indications for evaluation of acute diarrhea
depends on severity and duration
indications:
- profuse diarrhea with dehydration
- grossly bloody stools
- temp at or above 38.5
- duration longer than 48 hours without improvement
- recent antibiotic use
- new community outbreaks
- associated with severe abdominal pain in patients older than 50
- elderly (above age 70)
- immunocompromised patients
what should you think about in a patient presenting with diarrhea and severe abdominal pain, and they are older than 50
ischemic colitis
what to ask on history for acute diarrhea
onset and duration of symptoms
frequency and characteristics of stool
fever
peritoneal symptoms
nausea/vomiting
occupational exposure
travel history
pets, hobbies
sick contacts
diet–> unpasteurized, raw/uncooked
recent antibiotic use, laxative use
medication history
past medical history
weight loss
steatohhrea vs. leukocytes
what should you ask about the quality of the stool
blood?
fatty?
profuse watery?
frequency?
what should you ask specifically on PMHx
cancer immunosuppression UC crohns surgeries/short gut chemotherapy
what to look for on physical exam in diarrhea
vitals–> signs of dehydration, general appearance
extra-intestinal manifestations of IBD
abdo exam and rectal exam
list some extra-intestinal manifestations of IBD
arthritis –usually large joints
ankylosing spondylitis (stiffness, pain in spine, pelvis)
erythema nodosum (raised, tender, red or violet swelling 1.5 cm in diameter usually on legs)
Sweet’s syndrome—tender red nodules on upper limbs, face and neck sometimes with fever
pyoderma gangrenosum–small tender blisters that turn into deep ulcers
sores in mouth
episcleritis–red, sore, inflamed eye
scleritis
uveitis–inflammation of iris
kidney stones
gallstones
anemia
investigations to consider in acute diarrhea
CBCD, lytes, creatitine, urea
stool cultures–> C and S, O and P, C diff toxin
abdominal xrays
sigmoidoscopy
colonoscopy
treatment of acute diarrhea
fluid and electrolyte replacement therapy–PO vs IV depending on degree of dehydration
in moderately severe nonfebrile and non bloody diarrhea can consider antimotility and antisecretory agents such as loperamide to control symptoms
abx for travellers diarrhea, C diff or specific bacterial agents
diet modification
in which patients might loperamide/other antimotility and antisecretory agents be considered
moderately severe NONfebrile and NONbloody diarrhea
what usually causes chronic diarrhea
usually due to non infectious causes
diarrhea lasting more than 4 weeks warrants evaluation to exclude serious underlying pathology
what are the 5 classes of causes of chronic diarrhea
- secretory
- osmotic
- steatorrheal
- inflammatory
- dysmotility
list the secretory causes of chronic diarrhea
stimulant laxatives medications bile acids bowel resection (decreased absorption) bowel obstruction fecal impaction hormone producing tumours (carcinoid, vipoma, gastrinoma) addisons congenital defects in electrolyte absorption
what is the mechanism behind secretory diarrhea? how does it present?
due to derangements in fluid and electrolyte transport across the colonic mucosa
characterized by watery, large volume fecal outputs that are typically painless
persists with fasting
no stool/fecal osmolar gap
list osmotic causes of chronic diarrhea
osmotic laxatives magnesium containing antacids health supplements lactase deficiencies sorbitol, lactulose, polyethylene glycol
what is the mechanism of osmotic diarrhea and how does it present
occurs when ingested, poorly absorbed, osmotically active solutes draw fluid into the lumen exceeding the absorptive capacity of the colon
ceases with fasting or with discontinuation of the causative agent
stool/fecal osmolar gap present (above 50mosm/l)
list steatorrheal causes of chronic diarrhea
intraluminal maldigestion (pancreatic exocrine deficiency, bacterial overgrowth, bariatric surgery, liver disease)
mucosal malabsorption (celiac disease, whipples disease, infections, ischemia)
post mucosal obstruction (lymphatic disease)
what is the mechanism of steatorrheal diarrhea and how does it present
fat malabsorption may lead to greasy, foul smelling, difficult to flush diarrhea often associated with weight loss and nutritional deficiencies due to concomitant malabsorption of amino acids and vitamins
stool fat exceeds 7g/day
list causes of inflammatory chronic diarrhea
crohns
UC
immune related (immunodeficiencies, food, allergy, eosinophilic gastroenteritis)
infections (bacteria, viruses, parasites)
radiation injury
malignancies
what is the mechanism of inflammatory diarrhea and how does it present
usually accompanied by pain, fever, bleeding or other manifestation of inflammation
usually leukocytes present in stool analysis
with severe inflammation you can have anasarca
list causes of dysmotility chronic diarrhea
IBS
hyperthyroid
drugs–prokinetics
post vagotomy
what is the mechanism of dysmotility diarrhea
due to rapid transit
what to ask specifically on history for chronic diarrhea
B symptoms systemic symptoms--joint pain, eye redness, mouth ulcers, rashes pain aggravated or relieved by BM resolution with fasting occupation or travel exposure
what investigations should be considered in chronic diarreah
stool cultures stool osmolar gap anti TTG (celiac) leukocytes in stool stool fat analysis imaging/scopes
