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Flashcards in Lower GI 2 Deck (60):
1

Acute intestinal perforation - ssx:

sudden & catastrophic!
severe, generalized abd pain
signs of shock
N/V
anorexia

2

Acute intestinal perforation - causes:

in SI:
duodenal ulcer
corrosives
strangulation of the bowel
acute appendicitis

in LI:
obstruction
diverticulitis
IBD
toxic megacolon

3

Acute intestinal perforation - PE:
Work up:

quiet - absent bowel sounds
peritoneal signs: rigidity, guarding
w/underlying GI d/o -> looks like "worsening"

abd x-ray or CT -> free air seen

4

Gastroenteritis:

inflammation of the lining of the stomach, SI, & LI - most commonly from infx
typically self-limiting; serious in young, elderly, immunocompromised

typical GI inhabited by 500 bacterial species!

5

Gastroenteritis - ssx:

sudden onset N/V
anorexia
abd cramps
diarrhea
malaise
myalgia

6

Gastroenteritis - PE:
Work up:

distended abd
tenderness
borborygmi

stool testing - hemoccult, WBDc, O&P, culture
rapid enzyme - viral, shiga
CBC, CMP (hypokalemia)

7

Viral gastroenteritis - prevalence:
Types:

30-40% of infectious diarrhea in the US

Rotavirus
Norovirus
Astrovirus
Enteric adenovirus
In immunosuppressed -> CMV & enterovirus

8

Rotavirus:
Ssx:

MC worldwide
33% of hosp admit/20% death assoc w/GE
highly contagious - fecal-oral
peaks in winter (but yr round)

severe dehydrating diarrhea in kids (3-15 mos)
mild in adults
vomiting
fever >102F
lasts 5-7 days

9

Norovirus:
Ssx:

older children & adults
year round
highly contagious
can be endemic -> food, water-borne

acute onset vomiting
abd cramps
diarrhea
fever
HA
lasts 1-2 days

10

Astrovirus:
Ssx:

infants, young children
winter months
fecal-oral

six like rotavirus:
dehydrating diarrhea
vomiting
fever
lasts 5-7 days

11

Enteric adenovirus:
Ssx:

kids <2 yrs
year round/summer
fecal-oral

diarrhea - 1-2 wks
followed by mild vomiting

12

Bacterial gastroenteritis - 3 mechanisms:

exotoxin - secreted by organism, ingested in food; N/V, diarrhea 12hrs from ingestion, no blood/WBC in stool, abate in 36hrs

enterotoxin - cytotoxins specific for mucus membrane in intestine, secreted in vivo, impaired absorption

mucosal invasion - ingest organism, causes ulceration, bleeding, exudate; stool: WBC, RBC, mb gross blood; watery diarrhea - >1L/d, no fever, HA, myalgia; bloody diarrhea - abd pain, tenesmus, N/V, fever, malaise

13

Gastroenteritis - exotoxin organisms:

Staph aureus - MC
Bacillus cereus
Clostridium perfringens
Clostridium botulinum

14

Staph aureus GE:

most common food poisoning
introduced by food handlers
milk products, meat, potato salad

sudden, abrupt, severe vomiting - 2-6hrs post-ingest
explosive diarrhea
abd cramps
fever rare
lasts 3-6hrs, complete recovery

15

Bacillus cereus - GE:

spore-forming organism found in soil
contaminates food
survives high heat

emesis - 2-6hrs post-ingest
severe vomiting
abd pain
mb diarrhea
no fever/no systemic

diarrhea - 8-16hrs post-ingest
foul smelling
profuse
nausea
abd pain
tenesmus

resolves 12-24hrs

16

Clostridium perfringens - GE:

spore-forming anaerobe
feces, soil, air, water
synthesized before ingestion, more after
beef, poultry, improper cooking/re-heating

watery diarrhea
foul-smelling
severe, crampy abd pain
8-16hrs post-ingest
resolves 24-36hrs

17

Clostridium botulinum - GE:

3 exotoxin types - A, B, E
1/3 of deaths from food-borne dz
improper home canning (A, B)
smoked fish (E)

4-8hr incubation
phase 1 - vague: fatigue, N/V, cramps, diarrhea
phase 2 - visual: diplopia, dec. acuity, ptosis, un-PERRLA
phase 3 - neuro: descending weakness/paralysis, dysphagia, sensorium okay, normal-low temp
65% mortality @2-9days
w/tx <10%

18

Gastroenteritis - enterotoxins:

Vibrio cholera
Enterotoxigenic E coli
Clostridium difficile

19

V. cholera - GE:

endemic in Asia
fecal-contaminated food/water
contaminated saltwater crab/freshwater shrimp
1-3day incubation

sudden, painless, profuse, watery diarrhea
no fever, N/V, blood, abd pain, tenesmus
water loss -> thirst, oliguria, mm cramps, weakness
cold, cyanotic skin
dehydration
hypoTN, tachycardia
recover 7-10days (if rehydrated)
50% fatal in untx severe

20

Enterotoxigenic E. coli - GE:

fecal-oral contaminated food/water
1-3day incubation
tissue invasion or enterotoxin

profuse, watery diarrhea
3-5days

21

C. diff - GE:

overgrowth of intrinsic organism post-abx
infx via external source (soil, water, pets)
cytotoxin & enterotoxin
pseudomembranous colitis
common nosocomial, iatrogenic

watery diarrhea
cramping abd pain
N/V rare

22

Toxic Megacolon:

d/t C. diff
dilated colon
fever
abd pain
tachycardia

PE: tender abd
absent bowel sounds

work up: elev. WBC
distended bowel on X-ray
colonoscopy contraindicated

23

Gastroenteritis - mucosal invasion:

salmonella
Campylobacter jejuni
Shigella
Enterohemorrhagic E col
Yersinia enterocolitica

24

Salmonella - GE:

ingestion of raw egg, chicken, milk
contact w/reptiles
req. large inoculum for infx
direct invasion -> exudative diarrhea
enterotoxin -> secretory diarrhea

watery (or bloody) stool
HA
malaise
N/V
abd pain
6-48hrs post-ingest
mb fever
self-limited to 7days

25

Campylobacter jejuni - GE:

MC cause of bloody diarrhea in US
contaminated pork/beef/lamb/milk/H2O/pets
incubation 1-7days

12-24hr prodrome:
HA
myalgia
malaise
then severe:
abd pain
fever
watery, then bloody, diarrhea
self-limit 7-10days

26

Shigella - GE:

MC in children 6mos-5yrs
contaminated food/H2O/milk or person-to-person
highly contagious - small inoculum
1-3day incubation

biphasic:
starts as low abd pain
diarrhea
fever in 50%
then 3-5 days:
rectal burning
tenesmus
small volume bloody stool
children - 1-3days
adults - 1-7days

27

Enterohemorrhagic E coli - GE:

0157:H7 strain
produces Shiga toxin
bovine reservoir - raw beef/milk
fecal-oral

acute onset >16hrs post-ingest
severe abd cramps
watery diarrhea
bloody w/in 24hrs
1-8days
5% complicated -> HUS or TTP

28

Yersinia enterocolitica - GE:

raw pork/milk or contaminated water

watery or bloody diarrhea
fever
may mimic appendicitis

29

Traveler's diarrhea:

Turista
caused by contact w/endemic organism
common: enterotoxic E coli & norovirus

N/V
borborygmi
abd pain, cramps
diarrhea
12-72hrs post-ingest
usu. self-limiting

fever & bloody diarrhea suggest more serious dz

30

Common parasites:

Giardia lamblia
Cryptosporidium parvum
Entamoeba histolytica

31

Giardia - GE:

fecal-oral, water or person-to-person
traveler's pathogen (low IgA, malnutrition, hypochlorhydria)
ingestion of cysts -> break down -> infx
7day incubation

mb asx
mild, watery diarrhea
abd bloating
cramps
flatulence 1-3wks
bulky stools
foul smelling
self-limiting to chronic

32

Cryptosporidium - GE:

high rate in HIV, immune-compromised, daycare
contaminated food/water/pets (CATS)

profuse, watery diarrhea
anorexia
low fever 5days post
~2 weeks

in immune-compromised:
chronic, watery diarrhea
up to 17days
dehydration

33

Entamoeba - GE:

endemic, travel-assoc, fecal-oral
HIV, AIDS, immunocompromised

mild:
crampy
abd pain
intermittent diarrhea
severe:
bloody diarrhea
abd pain
tenesmus
fever
toxic megacolon

34

Drug & chemical-related GE:

* Rx: antacids, abx, antihelminthics, colchicine, digoxin
* Heavy metal poisoning
* Laxative abuse
* Poisonous mushrooms or plants

35

IBD:

loss of tolerance to normal enteric flora
triggered by inc permeability, imbalanced flora, stress

Crohn's dz (regional enteritis)
Ulcerative colitis (UC)

36

Crohn's dz - presentation:

transmural inflammation of intestine (mesentery + nodes)
ulceration, fissure, fistula, granulomas
lesions btw areas of healthy tissue
cobblestone appearance - aphthous ulcers, skip lesions
exacerbations & remissions

37

Crohn's - etiology, risk factors, incidence:

unknown etio - genetic/infx/immuno/psych?
smoking
OCPs
diet: refined sugar, low fiber, high animal fat
dysbiosis, abx use
early appendectomy
15-25yrs or 55-65yrs
younger pop. 88% SI
2-4x higher Jewish
caucasian
A types
higher socioeconomic
F>M (slight)

38

Crohn's - ssx:

RLQ pain - steady, localized
fatigue
occult blood
stool: usu formed (lower = looser)
steatorrhea -> risk of gallstones
1/3 have perianal dz (fissure, fistula, abcess)

4 patterns:
inflammation- RLQ pain, like appendicitis
obstruction- severe colic, distention, constipation, V
diffuse jejunoileitis- 1+2 -> chronic debility
abd fistula/abcess- late w/fever, painful mass, wasting

39

Crohn's - PE:

RLQ tenderness, assoc fullness or mass
abd distension
fever
wt loss

40

Crohn's - complications:

intestinal obstruction!
fistula -> abscess
malabsorption
persistent UTI
pneumaturia
perforation -> hemorrhage (rare)
SCC

41

Crohn's - work up:

CBC - anemia, leukocytosis
inc ESR & CRP
low iron & vit B12
fecal lysozyme
serology: ASCA, ANCA

plain film + barium enema
upper GI contrast - string sign
CT [US, MRI]
colonoscopy - skip lesions, cobblestone appearance, longitudinal ulcers, narrowing, fistulas, sarcoid-type epithelial granulomas

42

Ulcerative colitis - presentation:

chronic, recurrent inflammatory disease of the colon or rectal mucosal layer.
superficial ulceration usu. involves rectum (95%)
continuous - NO skip areas

43

UC - etiology, risk factors:

immune-mediated, autoimmune
FHx -> higher risk
smoking -> negatively assoc (Crohn's more likely)
environmental factors
diet - dairy, sugar, low fiber, high fat
2-4x higher - Jewish; higher - caucasian
M>F (slight)
bimodal peak - 15-25 & 55-65yo

44

UC - ssx:

cramping abd pain
series of bloody diarrhea attacks, asx btw
stool with mucus, RBCs, WBCs - sigmoid
tenesmus, watery stool, pus, blood, mucus - proximal SI

systemic sx:
malaise, fever, anemia, wt loss

45

UC - complications:

hemorrhage - MC
toxic megacolon (danger of perforation)
dysplastic cells -> risk of colon CA

46

UC - work up:

CBC - anemia, low platelets
high ESR, CRP
CMP - low albumin, K, Mg; high alk phos
stool analysis

plain film - dilation, perforation, obstruction, ileus
barium enema - lead pipe appearance (loss of haustra)
flex sig - Dx
colonoscopy w/bx - confirm Dx, staging, monitoring

47

Compare & contrast UC & Crohn's:

USE CHART IN NOTES (in phone pics)

but really. do it.

48

IBS -

Dx of exclusion
MC GI disorder, 50% of pts to GE dr
high frustration, counseling needed

functional dyspepsia
spastic colitis
mucous colitis

49

IBS - etiology (postulated):

change in GI motility
hypersensitivity of visceral afferents
inc mast cells in gut - histamine
mm hyper-reactivity
psych illness
abn nmda receptors
HPA axis
SIBO
diet

50

IBS - red flag sx:

onset >50yo
severe, unrelenting diarrhea
nocturnal sx
wt loss
hematochezia
FHx of IBD, celiac, CA

51

IBS - Rome III criteria:

1. relieved by defacation
2. onset assoc w/change in frequency
3. onset assoc w/change in form/appearance

52

IBS - PE:

diffuse abd tenderness over colon

53

IBS - work up:

Labs (used to dx/rule out other causes)
CBC, CMP, hemoccult, breath test, celiac

x-ray - motility (spasm)
flex sig - mucus, spasm (or asx)

54

SIBO:

small intestine bacterial overgrowth
inc # or type -> fermentation, inflammation, malabsorption
gases & toxins produced

55

SIBO - overgrowth prevented by:

antegrade peristalsis
gastric acid
bile
proteolytic enzymes
sIgA
intact IC valve

56

SIBO - causes:

anatomical anomalies - diverticula, stricture
insufficient enzyme
abn motility
abn communication - fistula, bad valve
immunocompromise
alcoholism/cirrhosis
pancreatitis

57

SIBO - Hx:

transient improvement in sx post-abx
worse w/ probiotic tx
worse w/ inc fiber intake

58

SIBO - ssx:

abd pain/cramps
borborygmus
eructation
flatulence
bloating
watery diarrhea alternative w/constipation
systemic - HA, jt pain, fatigue, rosacea

59

SIBO - PE:

abd distension
succussion splash
surgical scar?

60

SIBO - work up:

CBC - macroscopic (B12) or micro anemia, low ferritin
Glucose breath hydrogen analysis (H2)
methane breath test
endoscopy w/jejunal aspirate