Diarrhea Flashcards
Do most patients with diarrhea present for care?
No
Do most cases of diarrhea need tx?
No
What are most cases of diarrhea?
Infectious
Most cases of infectious diarrhea are what?
Viral
Most cases of viral diarrhea are what?
Norovirus
Most cases of severe diarrhea are what?
Bacterial
Most cases of bacterial diarrhea are what?
Campylobacter
Diarrheal diseases represent what?
One of 5 leading causes of death world wide
Approach to patients with diarrhea focuses on what?
Distinguishing infectious etiologies from non infectious etiologies
Definition of diarrhea
Decreased absorption or increased secretion (or both) causing >200 grams of stool a day - in dry weight
3x in a 24hr period
Diarrhea reflects what?
Impaired water absorption or increased water secretion by the bowel
What is acute diarrhea? Likely what?
Acute is 14 days or less, likely infectious
What is persistent/subacute diarrhea? Could be what?
More than 14 days but <30 days
Could be inflammatory or infectious
What is chronic diarrhea? What are the 3 types?
> 30 days
3 types: osmotic, secretory and inflammatory vs non-inflammatory
Small bowel vs large bowel functions
Small bowel - functions as a fluid and enzyme secreting/regulating organ
-ABSORBS NUTRIENTS
Large bowel - absorbs fluid and salt
-EXCRETES K
Dysregulation of what 2 processes leads to watery diarrhea?
Dysregulation of small bowel and large bowel processes leads to watery diarrhea
What are the major causes of acute infectious diarrhea?
Viruses - norovirus, rotavirus, adenovirus, astrovirus
Bacteria - Salmonella, Campylobacter, Shigella, entertoxigenic, E. Coli, C. Dif
Protozoa - cryptosporidium, guardia, cyclospora
When do non-infectious etiologies of diarrhea become more likely?
As the course of diarrhea becomes more persistent and chronic
When is Acute Evaluation of diarrhea warranted?
- persistent fever
- bloody diarrhea
- severe abdominal pain (they look like toxic megacolon)
- sx’s of volume depletion (hypotension, scant urine)
- hx of inflammatory bowel disease
- possible widespread food-borne outbreak
What is the most common etiology of diarrhea?
Viruses
Evaluation of diarrhea
- good hx
- character of sx’s, duration
- food hx
- exposure, pets
- travel
- meds/medical hx
- volume status
What determines whether diarrhea originates from small or large bowel?
Frequency and nature of stool
Different pathogens depending on if small or large bowel diarrhea
Diarrhea of small bowel sx’s
- watery
- large volume
- abd cramping
- bloating
- gas
- weight loss w/ persistent diarrhea
- rarely occurs with fever, occult blood or inflammatory cells in stool
Diarrhea of large bowel sx’s
- frequent, regular
- small volume
- painful bowel movements
- fever
- bloody or mucoid stools common
- inflammatory and red blood cells seen on microscopy
Diarrhea of large bowel suggests what?
Invasive bacteria (salmonella, shigella, or campylobacter)
Enteric virus (cytomegalovirus or adenovirus)
Cytotoxic organism (C. Diff)
Enterotoxic cause of diarrhea - what’s the diarrhea look like? Fever, WBC, Fecal leukocytes?
Infectious agent creates a toxin floating in gut causing large amount of WATERY DIARRHEA
NO FEVER, NO ELEVATED WBC, NO FECAL LEUKOCYTES
Invasive diarrhea - what’s the diarrhea like? Fever? WBCs? Fecal leukocytes?
The infectious agent breaks thru the blood/gut barrier - BLOODY DIARRHEA
FEVERS, LEUKOCYTOSIS, + FECAL LEUKOCYTES
Difference b/w diarrhea in enterotoxic causes and invasive causes?
Enterotoxic diarrhea is WATERY DIARRHEA
Invasive diarrhea is BLOODY DIARRHEA
Food hx timing and diarrhea
Within 6 hrs - ingestion of a preformed toxin (staph aureus or Bacillius cereus) esp if N/V
8-16 hrs - infection with C. Perfringens
> 16 hrs - other bacterial or viral infection
If get diarrhea within 6 hrs of eating, what is the cause?
Ingestion of a preformed toxin
(Staph aureus or B. Cereus) esp if N/V
If get diarrhea within 8-16 hrs after eating, what is it?
Infection with C. Perfringens
If get diarrhea >16 hrs after eating, what is it?
Other bacterial or viral infection
If have vomiting and diarrhea, what’s the most likely cause?
Viral
Bacterial doesn’t have as much vomiting
Other exposures that cause diarrhea
Animals - Salmonella
Travel - bacterial diarrhea and parasitic infections
Daycare centers - Shigella, Cryptosporidium and Giardia
Recent Abx use - C. Diff
When do you do stool cultures for diarrhea?
Severe illness - profuse watery diarrhea with signs of hypovolemia
Signs and sx concerning for inflammatory diarrhea
High-risk host features (age >70, etc)
What classifies severe illness for stool cultures?
Profuse watery diarrhea w/signs of hypovolemia
Passage of >6 unformed stools in 24 hrs
Severe abd pain
Need for hospitalization
Signs and sx’s concerning for inflammatory diarrhea
Bloody diarrhea
Passage of many small volume stools containing blood or mucous
Temp >101.3
High-risk host features that you should do stool cultures for diarrhea
Age >70
Comorbidities, CV disease, DM
Immunocompromised
IBD
Pregnancy
Sx’s >1 week
Public health concern
How to dx campylobacter, salmonella, shigella
Culture and sensitivity
Dx evaluations of diarrhea O&P stool study
Parasites such as Giardia and Strongylodies and entero-adherent bacteria can be difficult to detect but may be dx by intestinal bx
Fecal Leukocytes and dx evaluation of diarrhea
May also support the dx of inflammatory diarrhea, more sensitive is Fecal Lactoferrin (but not widely used)
What is fecal lactoferrin?
Used for diarrhea dx
Used to detect inflammation in the intestines, most sensitive than fecal leukocytes
Can be used to detect bacterial infections that cause inflammatory diarrhea
Sensitive and specific, but limited use
What is the first thing to assess when pt presents with diarrhea?
Hydration status and electrolytes b/c death from diarrhea is caused by DEHYDRATION
Severe diarrhea tx needs what?
IV with added K+ or NaHCO3-
Oral Rehydration Solution (ORS) tx for diarrhea
Given to infants and children at rate of 50-100ml/kg in 4 hrs
Adults should drink 1L/hr
Is NOT eating recommended as tx for diarrhea?
NO!!! Not necessary and not recommended
What should you avoid when have diarrhea?
Dairy
Caffeinated beverages - will enhance intestinal motility
Pharmacologic management of diarrhea
Anti-motility Rx (Bismuth subsalicylate)
Anxiolytics and antiemetics
-decr sensation of having to go (may make sx’s more tolerable, but don’t treat diarrhea)
Food derived substances (zinc and pectin)
Probiotics (keep good bacteria balanced in gut)
what meds make diarrhea sx’s more tolerable?
anxiolytics and antiemetics
-decr sensation of having to go (may make sx’s more tolerable, but don’t treat diarrhea)
Norovirus common where?
cruise ships, dorms
when do norovirus sx’s develop and how long do they last?
within 12-48 hrs after being exposed and last 24-72hrs
acute onset sx’s of Norovirus
N/V
watery, NON-BLOODY diarrhea
abd cramps
how is Norovirus transmitted?
close contact with infected person
fecal-oral route with contaminated food
touching contaminated surfaces
who can norovirus be serious for?
children and elderly
what is the most common complication of norovirus?
dehydration
-just hydrate, don’t usually need to go to ER
types of bacterial diarrhea
C. Diff, campylobacter, salmonella, Enterohemorrhagic E. coli, shigella, cholera
what can the toxins of C. diff cause?
- Severe watery diarrhea
- Pseudomembranous colitis
- Toxic megacolon
when do sx’s for c. diff develop?
Symptoms may develop while still on ABX or 5-10 days after completion
-timing of when you started abx is important
what abx are most frequently associated with C. diff?
- fluoroquinolones
- Cephalosporins
- PCNs
when should C. diff be suspected?
in patients with diarrhea (>3 watery stools in 24 hours) or ileus in the setting of relevant risk factors:
- ABX use
- Recent hospitalization
- Advanced age
what culture should you do for dx of C. diff?
stool culture
C. diff treatment
Metronidazole (Flagyl) - FIRST LINE
Vancomycin PO - 2nd line
Fecal transplant - if meds fail
what is the first line treatment for C. diff?
Metronidazole
what 2 species of campylobacter cause most of human disease-enteritis?
C. jejune and C. coli
what does campylobacter inhabit?
intestinal tracts of animals -> POULTRY
campylobacter sx’s
Abrupt onset of:
- Abdominal pain (can mimic appendicitis - RLQ pain)
- Diarrhea (bloody or mucoid)
- INVASIVE diarrhea
Prodrome of fever, chills, aches in 30%
campylobacter dx
stool culture
campylobacter tx in healthy pts
IV fluids and antiemetics
campylobacter tx in immunocompromised and severe disease
Cipro/Levo or Azithromycin
what is the leading cause of foodborne disease in the US?
non-typhoidal salmonellosis
most common salmonella species?
Salmonella enteritidis and Salmonella typhimurium
what food is salmonella associated with?
ingestion of poultry, milk products, eggs
when does salmonella gastroenteritis occur?
8-72hrs post exposure to ingestion of contaminated food or water
sx’s of salmonella gastroenteritis? resolves when?
INVASIVE!!!
- N/V
- Diarrhea (pea soup) - not grossly bloody, but may have blood
- abd cramping
- fever with chills
resolves in 48-72 hrs
salmonella dx
stool culture
salmonella tx
- Self-limiting 4-10 days
- Supportive
- IV fluid replacement and electrolyte repletion
- ABX not indicated in healthy patients
- Cipro or Levo for severe disease or immuncompromised
what is short-term vs long-term carriage of salmonella?
Short term carriage - normal shedding of bacteria after infection
Long term carriage - shedding of bacteria for more than 1 year after infection
sx’s of enterohemorrhagic e.coli diarrhea
Invasive
- abd pain
- BAD BLOODY DIARRHEA
- no fever
tx for enterohemorrhagic e.coli diarrhea
ABX NOT RECOMMENDED may increase incidence of hemolytic uremic syndrome (HUS)
-HUS = acute renal failure, hemolytic anemia, thrombocytopenia
Shigella also has high risk of HUS
what bacteria have a high risk of hemolytic uremic syndrome (HUS) when treated with abx?
e.coli and shigella
what is HUS?
hemolytic uremic syndrome
acute renal failure, hemolytic anemia, thrombocytopenia
why aren’t abx recommended to treat enterohemorrhagic E. coli?
b/c of hemolytic uremic syndrome (HUS)
what type of bacteria is Shigella?
Gram negative facultative anaerobe -> non spore forming bacteria
what is Shigella less susceptible to vs other bacteria?
stomach acid
-multiplies in small bowel
transmission of shigella
- Direct person to person contact
- Contaminated food and water
- Humans are the only natural reservoir
- Spread by fecal-oral route
- Predominantly institutions like day-care centers
- MSM
shigella sx’s
Invasive
- high fever
- diarrhea (small volume, bloody and mucoid, but may initially be watery)
- abd cramping
- tenesmus
shigella dx
stool culture
shigella tx
- Supportive
- IV fluids and electrolyte repletion
- Self limiting -> averages 7 days
- ABX not indicated in healthy patients because of risk of HUS
-Cipro, azithromycin, and Bactrim for severe disease and immunocompromised
what abx do you use for shigella and when?
Cipro, azithromycin, and Bactrim for severe disease and immunocompromised
what is cholera?
Acute secretory diarrheal illness cause by toxin producing strains of vibrio cholera
Secretory -> TONS of fluid
cholera sx’s
Massive diarrhea
- Non bloody
- Liquid
- Gray, RICE WATER STOOL***
- No odor
Profound fluid and electrolyte loss in stool and rapid progression to hypovolemic shock within 24 hours of symptom onset d/t nothing being absorbed
what can occur when have cholera?
Profound fluid and electrolyte loss in stool and rapid progression to hypovolemic shock within 24 hours of symptom onset d/t nothing being absorbed
cholera tx
HYDRATION!!!
Abx:
- tetracyclines
- ampicillin
- azithromycin
- bactrim
- FQs
where does cholera primarily affect in the world?
places with inadequate access to clean water
when does cholera peak?
before and after rainy seasons
types of protozoan induced diarrhea?
intestinal entamoeba
cryptosporidium
giardia
what is intestinal entamoeba?
type of protozoan induced diarrhea
caused by entamoeba hystolytica
poor sanitation
who is at increased risk of infection of intestinal entamoeba?
Institutional patients (prisons, nursing facilities) and MSM are at increased risk of infection
transmission of intestinal entamoeba?
Parasite exists in two forms
-Cyst stage -> infective form -> what gets passed on
-Trophozoite -> invasive disease form -> turns into this after cyst is ingested -> this is what does the damage -> causes BLOODY DIARRHEA
Can be associated with fecal-oral route
infection of intestinal entamoeba caused by?
ingestion of amebic cysts via contaminated food or water
sx’s of intestinal entamoeba
- Majority are asymptomatic
- Onset is 1-3 weeks
- Ranges from mild diarrhea -> severe dysentery, abdominal pain, weight loss, fever
- INVASIVE
intestinal entamoeba dx
O&P (ovum and parasite) culture
serum antigen
complications of intestinal entamoeba
Fulminant colitis with bowel necrosis leading to perforation and peritonitis
tx of intestinal entamoeba
- Metronidazole
- Tinidazole
- Ornidazole
what is giardia?
type of protozoan diarrhea cause
one of 2 common intestinal parasites found in US (with cryptosporidium)
giardia sx’s
- Watery, YELLOW, foul smelling diarrhea
- Alternating between soft and greasy stools
- Associated fatigue and bloating
- Weight loss = as much as 10% of body weight
giardia transmission
Can be both epidemic and sporadic
Common cause of waterborne and foodborne diarrhea in daycare center outbreaks
HISTORY OF CAMPING -> fresh water
common hx with giardia infection?
HISTORY OF CAMPING
giardia tx
- Metronidazole
- Tinidazole
- Nitzoxinide
Even after treatment may have recurrent episodes up to 6 weeks
-Takes a while to get back to baseline
what is the most common parasitic cause of acute food borne diarrhea in US?
cryptosporidium
how does cryptosporidium infect?
Digest the cyst and excrete the cyst - no trophozoite like in intestinal entamoeba
Cryptosporidium transmission
Spread from an infected person or animal
Fecally contaminated food or water
Cryptosporidium tx
Antiparasitic med: Nitazoxanide
-Good for children because liquid form
what defines traveler’s diarrhea?
Diarrhea that develops during or within 10 days of returning from travel
what is the most common cause of traveler’s diarrhea? how long does it last?
e. coli non-hemorrhagic
- lasts 1-5 days
highest risk of traveler’s diarrhea where?
india, nepal, western/central africa
campylobacter as cause of traveler’s diarrhea most common where?
SE Asia
rotavirus as cause of traveler’s diarrhea most common where?
Jamaica and in kids
prevention of traveler’s diarrhea
- Prudent selection of food and drink (bottle only)
- Food that is thoroughly cooked
- Pasteurized dairy products
traveler’s diarrhea sx’s
- Depend on microbial etiology
- Malaise
- Anorexia
- Abdominal cramps
- Watery diarrhea
traveler’s diarrhea tx
- Cipro or Levo
- Can consider loperamide
when do you consider food borne illness?
Consider foodborne illness when patients present with diarrhea, N/V
Non-infectious causes of diarrhea
- Inflammatory bowel disease
- Irritable bowel disease
- Partial SBO
- Pelvic abscess in rectosigmoid region
- Fecal impaction
- Ingestion of poorly absorbable sugars -> lactulose
- Acute alcohol ingestion
what is irritable bowel syndrome?
chronic abdominal pain and altered bowel habits in absence of any organic cause
what is the most commonly diagnosed GI disorder?
irritable bowel syndrome
pathophysiology of IBS?
- GI motility
- Visceral hypersensitivity- nerves in gut are flared in response to something
- Inflammation
- Good sensitivity
- Bacterial overgrowth
definition of IBS
recurrent abdominal pain or discomfort on average at least 1 day per week in last 3 months with 2 or more of the following:
- Improvement with defecation
- Abdominal pain gets better with shitting
- Change in frequency of stool
- Change in form of stool
definition of IBS with constipation
abnormal bowel movements are usually constipation
definition of IBS with diarrhea?
abnormal bowel movements are usually diarrhea
definition of mixed IBS
abnormal bowel movements are both constipation and diarrhea
indications for endoscopic evolution for IBS
- More than minimal rectal bleeding
- Weight loss
- Unexplained iron deficiency anemia
- Nocturnal symptoms
- Ask if it wakes them up at night (usually means inflammatory diarrhea)
- Family history of colorectal cancer, inflammatory bowel disease, or celiac sprue
IBS tx
Dietary modification
- Eat low gas producing foods
- Avoid beans, onions, celery, bananas, apricots, bagels, pretzels
- Avoid alcohol and caffeine
- Avoid lactose
- Low FODMAP diet: fementable foods (Honey, corn syrup, apples, pears, mangoes, cherries)
- Avoid gluten
Physical activity
pharmacologic therapy for IBS-C
Mirilax (polyethylene glycol)
Lubiprostone - chloride channel activator that enhances chloride rich intestinal fluid secretion
Linaclotide - guanylate cyclase agonist that stimulates intestinal fluid secretion and transit
what is malabsorption caused by?
Caused by many different diseases, drugs, or nutritional products that impair:
- Intraluminal digestion
- Mucosal absorption
- Nutrient delivery to systemic circulation
what is the HALLMARK of malabsorption?
steatorrhea - excess fat in stool
- Bulky fat laden stool: >30g of fat per day
- Yellow, smelly, floating poop
what is the goal of tx for malabsorption?
Goal is to treat or correct underlying cause
- Celiac sprue
- Bacterial overgrowth
- Lactase deficiency
malabsorption GOLD STANDARD dx
Quantitative stool fat test
- Ingestion high fat diet for 2 days before and during collection -> 100 g of fat per day
- Stool collected for 3 days- totals 5 days
other malabsorption dx tests
Qualitative Sudan stain for fat
- Determines the percentage of fat in stool
- 90% sensitivity and specificity
Acid steatocrit
- Inexpensive and reliable
- Centrifugation of acidified stool in a liquid HCT capillary -> separates into solid, liquid and fatty layers
is oral better than IV for tx of diarrhea?
yes!!!
-unless severe dehydration, then use IVF (normal saline, ringer’s lactate)
what types of fluid solutions do you need to treat diarrhea?
ones that contain water, salt, and sugar (coke and sprite)
are oral rehydration fluids for sweat replacement equivalent?
no!!!
-These replace electrolytes, but not the same as what you need when you are dehydrated from diarrhea
- May however, be adequate in an otherwise healthy patient
- Has to do with osmolarity: low osmolarity oral rehydration fluids have been shown to decrease: Stool output, Vomiting, And need for IV fluids
antimotility meds as tx for diarrhea
Loperamide (Imodium)
Pepto-Bismal (Bismuth subsalicylate)
Lomotil (Atropine/Diphenoxylate)
Eluxadoline (combined opioid agonist/antagonist) - Slows down gut
Bile acid sequestrants
how does loperamide work and caution in what when using it?
Works by slowing down gut motility -> decreases number of stool and makes diarrhea less watery
CAUTION in invasive bacteria -diarrhea is acting to flush out bacteria, don’t want to slow that down or will get toxic megacolon
when are bile acid sequestrants used for tx of diarrhea? how do they work? how do bile acids cause diarrhea?
Used in patients with persistent diarrhea despite antidiarrheal use
Bile acids cause diarrhea by stimulating colonic secretion and motility
Cholestyramine, Colestipol, Colesevelam - will bulk up the stool
50% of patients with IBS-D will have what?
50% of patients with IBS-D have bile acid malabsorption
do all pts with diarrhea need antidiarrheal meds?
NO!!!
in some it is C/I!!!
