2: Infectious Diarrhea Flashcards
1
Q
describe normal stool volume
A
3-7 bowel movements/day
2
Q
describe acute infectious diarrhea volume
A
20-30 bowel movements/day
up to 20L stool/day
3
Q
diarrhea reflects increased water in stool from what two mechanisms
A
- increased intestinal secretion of water
2. decreased intestinal reabsorption of water
4
Q
what three things must you differentiate diarrhea from?
A
- pseudodiarrhea
- fecal incontinence
- overflow incontinence
5
Q
describe pseudodiarrhea
A
- rectal urgency
- related to anal infection
6
Q
describe fecal incontinence
A
-sudden discharge involuntarily
7
Q
describe overflow incontinence
A
-obstupation or chronic constipation, then overflow of liquid stool around the solid stool -> leaks out of rectum
8
Q
duration of each of the following:
- acute diarrhea
- persistent diarrhea
- chronic diarrhea
A
acute: less than 14d
persistent: 14-30d
chronic: more than 30d
9
Q
causes of acute diarrhea in healthy adults of developed countries
A
- usually viral
- more severe diarrhea more likely bacterial
- protozoa least common causes
10
Q
is stool culture high yield?
A
nope - about 1-6% of patients showed positive stool cultures
11
Q
S. aureus story
A
- incubation 1-6h
- major sx: vomit
- prepared food - salads, dairy, meat
- cream pie at picnic
12
Q
B. cereus story
A
- incubation 1-6h
- major sx: vomit
- rice, meat
- leftover fried rice
13
Q
Norwalk-like virus story
A
- incubation 24-48h
- major sx: vomit
- shellfish, prepared foods, salads, sandwiches, fruit
- cruise ships
14
Q
non-typhoidal salmonella story
A
- incubation 1-3d
- major sx: inflammatory diarrhea
- eggs, poultry, meat, unpasteurized milk or juice, fresh produce
- hamburgers at picnic
15
Q
shiga toxin-producing E. coli story
A
- incubation 1-8d
- major sx: inflammatory diarrhea
- ground beef, unpasteurized millk and juice, raw vegetables, water
- E. coli O157:H7 - hamburgers, spinach
16
Q
v. parahemolyticus story
A
- incubation 2-48h
- major sx: inflammatory diarrhea
- raw shellfish
- sushi
17
Q
v. vulnificus story
A
- cirrhosis/ decreased immune system pt eating raw oysters in redneck riviera
- months without an “r”
- starts as GI issues
18
Q
review of C. perfringens
A
- enterotoxin produced by bacteria in small intestine
- acute gastroenteritis sx: acute watery diarrhea
- home-canned
-ingested bacteria can cause pig bel (necrotizing enteritis)
19
Q
review of C botulinum
A
- paralytic neurotoxin formed by bacteria present in anaerobic environment
- weakness, diplopia, progresses to paralysis
- botulism
20
Q
review of C tetani
A
- excitatory neurotoxin formed by bacteria present in wounds
- lockjaw
21
Q
review of C difficile
A
- toxin mediated colitis caused by overgrowth of C diff in colon
- pseudomembranous colitis
22
Q
norovirus story
A
- cruise ships
- schools
- nursing homes
- camps
- military barracks
- vegetables
- waterborne or foodborne
- shellfish-associated outbreaks
23
Q
rotavirus story
A
- day care
- nurseries
- Australia
24
Q
Hep A story
A
- 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)
