Editing Infective diarrhoea (section)

== '''Pathophysiology''' ==

* Classify based on mechanism
** Diarrhoea secondary to altered mucosal transport or secretory dysfunction
*** Can be caused by toxins from Staph, E coli, Vibrio cholerae
*** VIP and gastrin and calcitonin
*** Occurs independent of dietary intake and does not subside with fasting
*** No significant stool osmotic gap
** Osmotic diarrhoea
*** The presence of osmotically active, poorly absorbed solutes in the bowel lumen that inhibit normal water and electrolyte absorption
*** Lactulose, magnesium, undigested lactose
*** Increased osmotic load can be measured in the stool
*** Subsides with fasting
** Diarrhoea secondary to malabsorption
*** Pancreatic insufficiency, biliary disease, Crohn's, coeliac, intestinal lymphangiectasia
*** Bile salts
** Exudative diarrhoea
*** Anything producing blood, pus or protein
** Diarrhoea secondary to altered bowel motility
* Classify based on location
** Right-sided colitis is classically salmonella, campylobacter, or yersinia

{| class="wikitable"
| 
|'''Likely pathogens'''
|'''Mean incubation period'''
|'''Classic/common food sources'''
|'''Other epidemiologic clues and background'''
|'''Treatment'''
|-
|'''Watery diarrhea'''
|Norovirus
|24 to 48 hours
|Shellfish, prepared foods, vegetables, fruit
|
* Outbreaks in:
* Restaurants
* Health care facilities
* Schools and childcare centers
* Cruise ships
* Military populations
|
|-
|
|''Clostridioides'' (formerly ''Clostridium'') ''difficile''*
|N/A
|N/A
|
* Antibiotic use
* Hospitalization
* Cancer chemotherapy
* Gastric acid suppression
* Inflammatory bowel disease
|
|-
|
|''Clostridium perfringens''
|8 to 16 hours
|Meat, poultry, gravy, home-canned goods
|
|
|-
|
|Enterotoxigenic ''Escherichia coli''
|1 to 3 days
|Fecally contaminated food or water
|
* Travel to resource-limited settings
|
|-
|
|Other enteric viruses (rotavirus, enteric adenovirus, astrovirus, sapovirus)
|10 to 72 hours
|Fecally contaminated food or water
|
* Daycare centers
* Gastroenteritis in children
* Immunocompromised adults
|
|-
|
|''Giardia lamblia''
|7 to 14 days
|Fecally contaminated food or water
|
* Daycare centers
* Swimming pools
* Travel, hiking, camping (particularly when there is contact with water in which beavers reside)
|
|-
|
|''Cryptosporidium parvum''
|2 to 28 days
|Vegetables, fruit, unpasteurized milk
|
* Daycare centers
* Swimming pools and recreational water sources
* Animal exposure
* Chronic diarrhea in advanced HIV infection
|
|-
|
|''Listeria monocytogenes''
|1 day (gastroenteritis)
|Processed/delicatessen meats, hot dogs, soft cheese, pâtés, and fruit
|
* Pregnancy
* Immunocompromising condition
* Extremes of age
|
|-
|
|''Cyclospora cayetanensis''
|1 to 11 days
|Imported berries, herbs
|
* Chronic diarrhea in advanced HIV infection
|
|-
|
|''Cholera''
|
|
|Profuse watery diarrhoea
|Supportive/azithromycin
|-
|'''Inflammatory diarrhea'''

'''(fever, mucoid or bloody stools)'''¶
|Nontyphoidal ''Salmonella''
|1 to 3 days
|Poultry, eggs, and egg products, fresh produce, meat, fish, unpasteurized milk or juice, nut butters, spices
|
* Animal contact (petting zoos, reptiles, live poultry, other pets)
* Travel to resource-limited settings
|
|-
|
|''Typhoidal salmonella (subtypes of Salmonella bacteria which can cause typhoid fever)''
|
|Meat/eggs
|
* Returned travellers
* Treat with ciprofloxacin, or ceftriaxone/metronidazole
* Separate salmonella
|
|-
|
|''Campylobacter'' spp
|1 to 3 days
|Poultry, meat, unpasteurized milk
|
* Travel to resource-limited settings
* Animal contact (young puppies or kittens, occupational contact)


Gram negative rod

20% need antibiotics
|Azithromycin 3 days if invasive or unwell
|-
|
|''Shigella'' spp


Gram negative rod

Direct damage to colon with toxins
|1 to 3 days
|Raw vegetables
|
* Daycare centers
* Crowded living conditions
* Men who have sex with men
* Travel to resource-limited settings
|Ceftriaxone
|-
|
|Enterohemorrhagic ''E. coli''


A.k.a. Shiga-toxin producing E. coli (STEC)
|1 to 8 days
|Ground beef and other meat, fresh produce, unpasteurized milk and juice
|
* Daycare centers
* Nursing homes
* Extremes of age
|
|-
|
|''Yersinia'' spp
|4 to 6 days
|Pork or pork products, untreated water
|
* Abnormalities of iron-metabolism (eg, cirrhosis, hemochromatosis, thalassemia)
* Blood transfusion
|
|-
|
|''Vibrio parahemolyticus''
|1 to 3 days
|Raw seafood and shellfish
|
* Cirrhosis
|
|-
|
|''Entamoeba histolytica''
|1 to 3 weeks
|Fecally contaminated food or water
|
* Travel to resource-limited settings
* Men who have sex with men
|
|-
|Others
|''CMV''
|
|
|Test by serology - viral load in blood

Endoscopy - patchy mucosal erythema in the colon, with inclusion bodies seen on biopsy, which are pathognomic for CMV.

Supportive treatment with addition of ganciclovir.
|
|-
|Typhlitis
|''Neutropaenic enterocolitis''
|Day 10-14 post chemotherapy

Can occur in any myelosuppressed or immunosuppressed patients
|Affects caecum, adjoining ileum and ascending colon. Watery or bloody diarrhoea in only half of patients.
|Operate if peritonitis, free gas, persistent bleeding (resect entire involved segment, regardless of how normal the serosa looks, and do not anastomose).

Tazocin until recovery from neutropaenia and resolution of symptoms, bowel rest, consider NGT, stool spec. Consider G-CSF for severely neutropaenic and unwell patients, however controversial.
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