Acute intestinal perforation - ssx:
sudden & catastrophic! severe, generalized abd pain signs of shock N/V anorexia
Acute intestinal perforation - causes:
in SI: duodenal ulcer corrosives strangulation of the bowel acute appendicitis
in LI: obstruction diverticulitis IBD toxic megacolon
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
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!
Gastroenteritis - ssx:
sudden onset N/V anorexia abd cramps diarrhea malaise myalgia
Gastroenteritis - PE:
Work up:
distended abd
tenderness
borborygmi
stool testing - hemoccult, WBDc, O&P, culture
rapid enzyme - viral, shiga
CBC, CMP (hypokalemia)
Viral gastroenteritis - prevalence:
Types:
30-40% of infectious diarrhea in the US
Rotavirus Norovirus Astrovirus Enteric adenovirus In immunosuppressed -> CMV & enterovirus
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
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
Astrovirus:
Ssx:
infants, young children
winter months
fecal-oral
six like rotavirus: dehydrating diarrhea vomiting fever lasts 5-7 days
Enteric adenovirus:
Ssx:
kids <2 yrs
year round/summer
fecal-oral
diarrhea - 1-2 wks
followed by mild vomiting
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
Gastroenteritis - exotoxin organisms:
Staph aureus - MC
Bacillus cereus
Clostridium perfringens
Clostridium botulinum
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
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
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
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%
Gastroenteritis - enterotoxins:
Vibrio cholera
Enterotoxigenic E coli
Clostridium difficile
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
Enterotoxigenic E. coli - GE:
fecal-oral contaminated food/water
1-3day incubation
tissue invasion or enterotoxin
profuse, watery diarrhea
3-5days
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
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
Gastroenteritis - mucosal invasion:
salmonella Campylobacter jejuni Shigella Enterohemorrhagic E col Yersinia enterocolitica
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
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
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
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
Yersinia enterocolitica - GE:
raw pork/milk or contaminated water
watery or bloody diarrhea
fever
may mimic appendicitis
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
Common parasites:
Giardia lamblia
Cryptosporidium parvum
Entamoeba histolytica
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
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
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
Drug & chemical-related GE:
- Rx: antacids, abx, antihelminthics, colchicine, digoxin
- Heavy metal poisoning
- Laxative abuse
- Poisonous mushrooms or plants
IBD:
loss of tolerance to normal enteric flora
triggered by inc permeability, imbalanced flora, stress
Crohn's dz (regional enteritis) Ulcerative colitis (UC)
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
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)
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
Crohn’s - PE:
RLQ tenderness, assoc fullness or mass
abd distension
fever
wt loss
Crohn’s - complications:
intestinal obstruction! fistula -> abscess malabsorption persistent UTI pneumaturia perforation -> hemorrhage (rare) SCC
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
Ulcerative colitis - presentation:
chronic, recurrent inflammatory disease of the colon or rectal mucosal layer.
superficial ulceration usu. involves rectum (95%)
continuous - NO skip areas
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
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
UC - complications:
hemorrhage - MC
toxic megacolon (danger of perforation)
dysplastic cells -> risk of colon CA
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
Compare & contrast UC & Crohn’s:
USE CHART IN NOTES (in phone pics)
but really. do it.
IBS -
Dx of exclusion
MC GI disorder, 50% of pts to GE dr
high frustration, counseling needed
functional dyspepsia
spastic colitis
mucous colitis
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
IBS - red flag sx:
onset >50yo severe, unrelenting diarrhea nocturnal sx wt loss hematochezia FHx of IBD, celiac, CA
IBS - Rome III criteria:
- relieved by defacation
- onset assoc w/change in frequency
- onset assoc w/change in form/appearance
IBS - PE:
diffuse abd tenderness over colon
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)
SIBO:
small intestine bacterial overgrowth
inc # or type -> fermentation, inflammation, malabsorption
gases & toxins produced
SIBO - overgrowth prevented by:
antegrade peristalsis gastric acid bile proteolytic enzymes sIgA intact IC valve
SIBO - causes:
anatomical anomalies - diverticula, stricture insufficient enzyme abn motility abn communication - fistula, bad valve immunocompromise alcoholism/cirrhosis pancreatitis
SIBO - Hx:
transient improvement in sx post-abx
worse w/ probiotic tx
worse w/ inc fiber intake
SIBO - ssx:
abd pain/cramps borborygmus eructation flatulence bloating watery diarrhea alternative w/constipation systemic - HA, jt pain, fatigue, rosacea
SIBO - PE:
abd distension
succussion splash
surgical scar?
SIBO - work up:
CBC - macroscopic (B12) or micro anemia, low ferritin
Glucose breath hydrogen analysis (H2)
methane breath test
endoscopy w/jejunal aspirate
