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Flashcards in 2: Infectious Diarrhea Deck (55)
1

describe normal stool volume

3-7 bowel movements/day

2

describe acute infectious diarrhea volume

20-30 bowel movements/day
up to 20L stool/day

3

diarrhea reflects increased water in stool from what two mechanisms

1. increased intestinal secretion of water
2. decreased intestinal reabsorption of water

4

what three things must you differentiate diarrhea from?

1. pseudodiarrhea
2. fecal incontinence
3. overflow incontinence

5

describe pseudodiarrhea

-rectal urgency
-related to anal infection

6

describe fecal incontinence

-sudden discharge involuntarily

7

describe overflow incontinence

-obstupation or chronic constipation, then overflow of liquid stool around the solid stool -> leaks out of rectum

8

duration of each of the following:
-acute diarrhea
-persistent diarrhea
-chronic diarrhea

acute: less than 14d
persistent: 14-30d
chronic: more than 30d

9

causes of acute diarrhea in healthy adults of developed countries

1. usually viral
2. more severe diarrhea more likely bacterial
3. protozoa least common causes

10

is stool culture high yield?

nope - about 1-6% of patients showed positive stool cultures

11

S. aureus story

-incubation 1-6h
-major sx: vomit
-prepared food - salads, dairy, meat
*cream pie at picnic

12

B. cereus story

-incubation 1-6h
-major sx: vomit
-rice, meat
*leftover fried rice

13

Norwalk-like virus story

-incubation 24-48h
-major sx: vomit
-shellfish, prepared foods, salads, sandwiches, fruit
*cruise ships

14

non-typhoidal salmonella story

-incubation 1-3d
-major sx: inflammatory diarrhea
-eggs, poultry, meat, unpasteurized milk or juice, fresh produce
*hamburgers at picnic

15

shiga toxin-producing E. coli story

-incubation 1-8d
-major sx: inflammatory diarrhea
-ground beef, unpasteurized millk and juice, raw vegetables, water
*E. coli O157:H7 - hamburgers, spinach

16

v. parahemolyticus story

-incubation 2-48h
-major sx: inflammatory diarrhea
-raw shellfish
*sushi

17

v. vulnificus story

-cirrhosis/ decreased immune system pt eating raw oysters in redneck riviera
-months without an "r"
-starts as GI issues

18

review of C. perfringens

-enterotoxin produced by bacteria in small intestine
-acute gastroenteritis sx: acute watery diarrhea
-home-canned

-ingested bacteria can cause pig bel (necrotizing enteritis)

19

review of C botulinum

-paralytic neurotoxin formed by bacteria present in anaerobic environment
-weakness, diplopia, progresses to paralysis
-botulism

20

review of C tetani

-excitatory neurotoxin formed by bacteria present in wounds
-lockjaw

21

review of C difficile

-toxin mediated colitis caused by overgrowth of C diff in colon
-pseudomembranous colitis

22

norovirus story

*cruise ships
-schools
-nursing homes
-camps
-military barracks
-vegetables
-waterborne or foodborne
-shellfish-associated outbreaks

23

rotavirus story

*day care
-nurseries
-Australia

24

Hep A story

*MSM (men sex men)
*shellfish
*food workers
-overcrowding
-lack of clean water
-patients and staff of institutions
-day care centers
-IV drug users
-traverlers
-military barracks
-shellfish

25

Giardia lamblia story

*travel
*surface water drinking
-daycare centers
-swimming pools
-fruit salad

26

ETEC story

-traveler's to developing world
-traveler's diarrhea

27

C. diff story

-hospitalization
-inpatient or outpatient antibiotics or chemotherapy within the last several weeks
-daycare
*antibiotics!!!

28

V. cholerae

-acute, watery diarrhea (rice water stool), large volume
-no blood or pus in stool, no fever
-dehydration! - treat with ORT

29

history for patients complaining of diarrhea

-onset of abnormal bowel movements
-frequency in last 24h
-presence of blood, mucus
-do you have to get up in the night for bowel movements?(indicates more pathologic, osmotic cause)
-associated symptoms - skin/joint, fever, pain
-exposures - surface water drinking, camping, traveled
-any recent antibiotic use

30

bristol stool chart classifications

type 1: separate hard lumps, like nuts (hard to pass)
type 2: sausage-shaped but lumpy
type 3: like a sausage but with surface cracks
type 4: like a sausage or snake, smooth and soft
type 5: soft blobs with clear-cut edges
type 6: fluffy pieces with ragged edges, a mushy stool
type 7: watery, no solid pieces, entirely liquid

31

physical exam for patients complaining of diarrhea

-vital signs
-general
-abdominal exam - tenderness, evidence of surgical abdomen (need immediate surgery)
-musculoskeletal - arthritis comes with inflam bowel disease
-skin - associated rashes (watch for severe vasculitic rash)
-rectal exam

32

what are signs for surgical abdomen

-absence of bowel sounds
-diffuse, severely tender
-distended
-tympanitic
-rebound, guarding
-board-like rigidity

33

arthritis vs. arthralgia

arthritis - joints red, warm, swollen, tender, evidence of synovitis

arthralgias - just joint pain, no swelling or tenderness

34

what does a severe vasculitic rash look like?

non-blanching (like a bruise)

35

what are some anal pathologies that can be in differential?

-anal fissures - trauma, anal sex, constipation; usually not pathological; can cause hematochesia (bright red blood in stool), more benign
-hemorrhoids
-anal fistula - tend to be more severe issue, usually acquired from inflammatory bowel disease
-anorectal HPV (sometimes pt mistakes for hemorrhoids)

36

evaluation of acute diarrhea

study UpToDate chart in packet

37

role of testing in acute diarrhea

1. routine stool culture
2. ova/parasites
3. endoscopy

38

indications for ova/parasite culture

-3 specimens on alternate days (3d)

-persistent diarrhea
-persistent diarrhea following travel to Russia, Nepal

39

indications for endoscopy

-persistent bloody diarrhea

40

treatment of acute diarrhea: 5 options

-ORT
-symptomatic therapy
-probiotics
-dietary alterations
-empiric antibiotics

41

describe ORT

-1/2 tsp salt
-1/2 tsp baking soda
-4 Tbsp sugar
per L of water

42

describe symptomatic therapy of acute diarrhea

anti-motility agents
-loperamide (imodium)
-diphenoxylate (lomotil)

bismuth subsalicylate (pepto-bismol)

*don't give anti-motility to patients w/ C diff b/c can give them toxic megacolon

43

describe probiotics for acute diarrhea

-align
-culturelle

44

describe dietary alterations for acute diarrhea

-avoid dairy (temporary loss of lactase)
-low-residue diet ("white foods", cooked vegetables, low fat meats)

BRAT diet
-bananas
-rice
-applesauce
-toast

45

describe empiric antibiotics for acute diarrhea

-fluoroquinolone (cipro 500 mg BID, levofloxacin 500 mg QD x 3-5d)
-metronidazole 500 mg TID x 7d

directed therapy guided by culture results (Sanford Guide helpful)

46

chronic diarrhea: secretory type of watery diarrhea

-reduced water absorption
-nocturnal
-persists despite fasting

-microscopic colitis
-stimulant laxatives (senna)

47

chronic diarrhea: osmotic type of watery diarrhea

-related to intake

-osmotic laxatives (miralax)
-Olestra (Wow!)

48

chronic diarrhea: functional type of watery diarrhea

-hypermotility
-improves with fasting

-irritable bowel syndrome

49

chronic diarrhea: malabsorptive/osmotic type of fatty diarrhea

-bloating
-gas
-steatorrhea

-giardiasis
-celiac disease

50

chronic diarrhea: maldigestive type of fatty diarrhea

-loss of digestive fxn (meat fibers)

-chronic pancreatitis
-cystic fibrosis

51

chronic diarrhea: IBD type of inflammatory diarrhea

-WBCs
-pus
-blood

-ulcerative colitis
-Crohn's disease

52

chronic diarrhea: invasive type of inflammatory diarrhea

-infectious causes (pus)

-C diff

53

chronic diarrhea: neoplasia type of inflammatory diarrhea

-associated weight loss
-abdominal pain

-Colon carcinoma

54

which bugs cause diarrhea from the small bowel + what is the mechanism of each?

-Salmonella (dysentery - bloody)
-E. coli (dysentery - bloody)
-C. perfringens (preformed toxin - large volume, watery)
-S. aureus (preformed toxin - large volume, watery)
-B. cereus (preformed toxin - large volume, watery)
-V. cholerae (enterotoxin)
-Giardia lamblia (enteroadherent)

55

which bugs cause diarrhea from the colon + what is the mechanism of each?

-Campylobacter (dysentery - bloody)
-Shigella (dysentery - bloody)
-C. diff (cytotoxin - bloody, abdominal pain)
-E. coli O157:H7 (cytotoxin)
-E. histolytica (dysentery - bloody)