GI Part 3 Flashcards
What are the two main causes of Acute Mesenteric Ischemia?
- diminished bowel perfusion due to low CO (CHF, drugs or, most commonly, shock)
- occlusive disease of the vascular supply of the bowel (thrombosis or embolism)
SSX: Acute Mesenteric Ischemia
sever abdominal pain with minimal physical finding
sudden onset = arterial embolism
gradual onset = venous thrombosis
abd tenderness, guarding, absent bowel sounds with necrosis
When should Acute Mesenteric Ischemia be suspected?
pt > 50 with predisposing conditions and sudden onset of sever abdominal pain
T/F. Acute Mesenteric Ischemia is considered an emergency.
true
Imaging: Acute Mesenteric Ischemia
mesenteric angiography
abd plain film or ct
How is ischemic colitis different than Acute Mesenteric Ischemia?
episodic and transient from small vessel atherosclerosis
milder, slower onset sx: LLQ pain and rectal bleeding
not as emergent
When is a hernia of the abdominal wall an emergency?
when strangulated
When does hernia of the abdominal wall have sxs?
when strangulated
How is intestinal obstruction classified?
complete/partial
simple/strangulated
location
onset: acute/gradual
Name 5 causes of intestinal obstruction.
adhesions hernia tumor diverticulities foregin body volvulus intussusception fecal impation
SSX: intestinal obstruction (small intestine)
sudden onset periumbilical/epigastric cramping
vomiting
non-tender abdomen (w/o strangulation)
maybe dilated loops of bowel
What are ssx complete small intestinal obstruction?
obstipation
What are ssx partial small intestinal obstruction?
diarrhea
SSX: intestinal obstruction (colon)
gradual onset of pain obstipation vomiting abd. distension non-tender borborygmi
5 Causes of ileus
post-surgical appendicitis diverticulitis perforation AAA hypokalemia drugs MI
SSX: ileus
distention vomiting abdominal discomfort colicky pain watery stool
PE: ileus
absent bowel sounds
non-tender abdomen
Imaging: ileus
xray/ct: free air seen in colon
What some causes of acute intestinal perforation in the SI?
duodenal ulcer
corrosives
strangulation of bowel
acute appendicitis
What some causes of acute intestinal perforation in the colon?
obstruction
diverticulities
IBD
toxic megacolon
SSX: acute intestinal perforation
sudden and catastrophic severe generalized abd pain tenderness signs of shock n/v anorexia
PE: acute intestinal perforation
quiet to absent bowel sounds
peritoneal signs: guarding, rigidity
Imaging: acute intestinal perforation
xray/CT: free air seen in small intestine
What history questions do you want to ask specifically for gastroenteritis?
ingestion of potentially contaminated food or water, travel, contact with similarly ill person, medication use
General sxs: gastroenteritis
sudden onset nausea vomiting anorexia abd. cramps diarrhea maybe malaise, myalgia
What work-up do you want to do if for gastroenteritis?
stool testing- hemoccult, fecal, WBC, O&P, culture
rapid enzyme assays: viral antigens, shiga toxin
CBC, CMP
What is the most common cause of diarrhea worldwide?
Rotavirus
Compare Rotavirus and Norovirus in terms of presentation.
Rotavirus: vomiting, fever >102, sxs last 5-7 days
Norovirus: abd. cramps, diarrhea, HA, lasts 1-2 days
What part of the year does Rotavirus incidence peak?
winter months
Who’s most affected by enteric adenovirus and what is the pt. picture?
kids < 2 yo
diarrhea for 1-2 wks, mild vomiting
What sx does all viral gastroenteritis illnesses have?
vomiting
What is the most common food poisoning and what foods are associated with it?
staphylococcus aureus
custard, milk products, potato salad, salad dressing, coleslaw, processed meat/fish
Compare SSX of S. aureus and C. perfringens
S. aureus: sudden abrupt severe vomiting 2-6 hr. after ingesting explosive diarrhea, abd. cramps sxs last 3-6 hrs. rarely fever
C. perfringens:
watery diarrhea, smelly, crampy adb. pain, 8-16 hrs after ingestion
resolves in 24-36 hrs
What are the most common sources of Bacillus cereus?
contaminated rice or meat
SSX: Bacillus cereus
emesis (2-6 hours after eating)
diarrhea (8-16 hours): smelly, profuse, nausea
resolves in 12-24 hours
What are the most common sources of Clostridium perfringens?
beef and poultry
foods not adequately cooked and then reheated
Which bacteria produce exotoxin?
s. aureus
b. cereus
c. perfringens
c. botulinum
What is the most common source of Clostridium botulinum?
home-canned goods
SSX: Clostridium botulinum
incubation 4-8 hrs after ingesting
phase 1: vague
phase 2: visual
phase 3: neurological
What is the course of a clostridium botulinum infection?
65% mortality
2-9 days following ingestion
SSX: cholera
sudden, painless, profuse large volume, water diarrhea
no blood/mucus
no fever, abd. pain, vomiting or tenesmus
cold
hypotension, tachycardia
recovery in 7-10 days with adequate rehydration
SSx: Enterotoxigenic E. coli
profuse watery diarrhea for 3-5 days
incubation 1-3 days
Common causes of C. diff.
nosocomial or iatrogenic (antibx use)
SSX: C. diff
water diarrhea
cramping
abd. pain
no n/v usually
Complication of C. diff
TOXIC MEGACOLON
SSX: toxic megacolon
dilated colon
fever
abd. pain
tachycardia
PE: toxic megacolon
tender abd.
absent bowel sounds
Work up: toxic megacolon
elevated WBCs
distended bowel seen on xray
don’t do a colonoscopy!
Causes of Salmonella poisoning.
undercooked chicken or eggs
unpasteurized milk
reptiles
Compare salmonella and c. jejuni in terms of presentation
salmonella: water diarrhea, maybe bloody HA malaise N/V abd. pain 6-48 hr after ingestion maybe fever sxs usually last 1 week
c. jejuni: prodrome of HA myalgia malaise for 12-24 hrs then, severe abd. pain, high fever, profuse water diarrhea then, bloody diarrhea sxs usually last 7-10 days
What is the most common bacterial cause of bloody diarrhea in the US?
Campylobacter jejuni
Sources of Campylobacter jejuni
pork, lamb, beef, milk products, water, infected pets
Which bacteria use mucosal invasion?
salmonella c. jejuni shigella enterohemorrhagic e. coli y. enterocolitica
Who most commonly gets Shigella?
children 6mo-5 years
SSX: Shigella
lower abd. pain
diarrhea
fever (50%)
maybe biphasic: first presents with above sxs, then develops rectal burning, tenesmus, bloody
Which other virus presents like Rotavirus?
astrovirus
Which bacteria produce enterotoxins?
cholera (vibrio)
enterotoxigenic e. coli
c. diff
What the the main source for E. coli 0157:H7?
undercooked beef or unpasteurized milk
also fecal-oral (mostly with toddlers)
How does enterohemorrhagic e. coli present?
acute onset of abd. cramps
watery diarrhea > 16 hrs after ingestion
becomes blood within 24 hours
Complications of enterohemorrhagic e. coli
HUS: hemolytic anemia, thrombocytopenia, acute renal failure
TTP: HUS, fever, neurological deficits
What are the main sources of Y. enterocolitica infection?
undercooked pork, unpasteurized milk, contaminated water
SSX: Y. enterocolitica
watery/bloody diarrhea and fever
may look like appendicitis if in terminal ileum
Compare Giardia lamblia and Crytosporidium parvum in terms of presentation.
giardia: incubation 7 days
maybe asx or watery diarrhea, abd. bloating, cramps, flatulence for 1-3 wks. stools bulky, foul smelling
could be self limiting or recurrent
c. parvum:
profuse, watery diarrhea, anorexia, low-grade fever 5 days after ingestion. self-limiting ~2 weeks
What does c. parvum look like in an immunocompromised pt.?
chronic watery diarrhea up to 17 days
What are the ssx of severe entamoeba histolytica infection?
bloody diarrhea abd. pain tenesmus fever toxic megacolon
How do the lesions of Crohn’s and UC compare?
Crohn’s: transmural, skip lesion, granulomatous
can be found anywhere along the GI tract
UC: continuous lesions involving only the mucosa
restricted to the colon and rectum (always involves rectum)
Risk factors of Crohn’s
unknown, possibly genetic smoking OCP diet dysbiosis appendectomy early in life
What is the location and quality of the pain with Crohn’s compared to UC?
Crohn’s: RLQ, constant, no relieved by BM
UC: cramping pain, lower abdomen, relieved by BM
What is the difference in stool appearance in crohn’s and UC?
Crohn’s: not grossly bloody
UC: bloody
How does Crohn’s present?
abd. pain localized in RLQ occult blood common usually formed, maybe loose fat malabsorption 1/3 pt. with perianal dz
How does UC present?
Cramping abd. pain
series of attack of bloody diarrhea with asx intervals
increased urgency, lower abd. cramps, blood, mucus
stools become looser as more proximal colon is involved
may also have systemic sx: fever, malaise, wt. loss, anemia
What is the pattern of Crohn’s?
- inflammation
- obstruction
- diffuse jejunoileitis
- abd. fistulas and abscesses
What do you find on PE with Crohn’s?
RLQ tenderness with fullness/mass (no mass in UC)
abd. distension
fever
wt. loss
Complications of Crohn’s
intestinal obstruction fistula abscess perforation/hemorrhage increased risk for SCC
What labs would you want to run if you suspect Crohn’s?
CBC: anemia, leukocytosis
Increased ESR, elevated CRP (higher in UC)
low serum iron and b12
+ fecal lysozyme
serology: ASCA (higher in crohn’s), ANCA (higher in UC)
Imaging for Crohn’s
plain film with double contrast barium contrast
single contrast for upper GI: irregularity, stiffness, thickening of terminal ileum
CT and double contrast for small bowel
US and MRI if radiation exposure is an issue
colonoscopy: “skip areas” and “cobble stone appearance”
granulomas seen in intestinal wall in 50% pts.
Risk factors for UC
maybe AI genetic susceptibility environmental factors dietary factors NOT SMOKING (unlike crohn's)
Who’s at greatest risk for developing UC?
Jewish 2-4x
caucasians
males
15-25yrs and 55-65yrs
Complications of UC
Hemorrhage (most common)
Toxic megacolon
increased risk of colon cancer
Labs for UC
CBC: anemia, platelet count >350,000
elevated ESR and C-reactive protein
CMP: hypoalbuminemia, hypokalemia, hypomagnesemia, elevated alk phos
stool analysis for organisms
Imaging: UC
plain film: colonic dilation (if severe)
barium enema appropriate in mild cases: narrow, tubular, short colon with loss of haustral folds, psuedopolyps, lead pipe appearance
flexible sigmoidoscopy (can dx)
colonoscopy with biopsy confirms dx
What extra-intestinal manifestations are seen only with Crohn’s?
cholelithiasis
renal oxalate stones
vitamin b12 deficiency
aphthous ulcers
Name 5 other extra-intestinal manifestations that can be see with both Crohn’s and UC.
erythema nodosum conjunctivitis fatty liver hepatitis pyelonephritis
Red Flags features of IBS
sx onset after age 50 severe unrelenting diarrhea nocturnal sxs unintentional weight loss hematochezia fam hx of organic GI dz
What is the Rome III criteria for dx of IBS
recurrent abdominal pain for at least 3 days/month during previous 3 months associated with 2 or more of the following:
- relieved by defecation
- onset associated with a change in stool frequency
- onset associated with a change in stool form/appearance
clinical picture of IBS
crampy abd. pain constipation/diarrhea both or alternating increased colonic mucus production flatulence, bloating, nausea, anorexia anxiety/depression stress related sx appearance of health
PE findings IBS
diffuse abd. tenderness over colon
What labs would you run for IBS?
CBC, CMP, homoccult, stool examination, hydrogen breath test, celiac testing
How is IBS ultimately Diagnosed?
identify typical symptoms complete physical examination exclude alarm features r/o celiac colonoscopy in pts. >50yo to r/o CA
Causes of SIBO
anatomical anomalies
insufficient enzymes
abnormal motility
abnormal communication btw sm. and large bowel
immunocompromise, alcholism. cirrhosis, pancreatitis
What hx findings would make you think SIBO?
sxs improve after a antibiotic use
worsening of IBS with probiotic/prebiotic use
worsening of IBS with increased fiber intake
SSX: SIBO
abd. pain, cramping, borborygmus, erctation, flatulence, bloating, watery diarrhea may alternate with constipation
vomiting, heartburn, wt. loss, steatorrhea, systemic sxs
PE finding for SIBO
abd. distension
succussion splash
Work-up SIBO
CBC: anemia
Glucose breath hydrogen analysis
[14C]-d-xylose breath test (methane)
Jejunal aspirate during endoscopy
What causes diverticulitis?
low fiber diet high refined carbohydrates genetic aging meds colonic segmentation defects in colonic wall strength
SSX: diverticulosis
asx
maybe chronic LLQ abdominal pain, constipation
maybe rectal bleeding
Complications of diverticulitis
obstruction
dangerous perforation
SSX: diverticulitis
abd. pain: LLQ, steady, deep
fever/chills
colick and diffuse abd. pain with flatulence
altered bowel habits
n/v
rectal bleeding: bright red or wine colored
Concomintant sxs of diverticulitis
dysuria
pyuria
urinary frequency
What are some SSX of complications of diverticulitis
pneumaturia or recurrent UTI
feculent vaginal d/c
severe and generalized abd. pain, absent bowel sounds, fever
back or lower extremity pain
What are expected PE findings of diverticulitis?
localized abd. tenderness rebound tenderness, maybe mass low-grade fever DRE shows tenderness, stool color changes and extent of GI bleeding proctoscopic exam may show mass
Imaging: diverticulitis
sigmoidoscopy: narrowing and inflammation
NO BARIUM X-RAY
SSX lactose intolerance
varies from minor abd. discomfort and bloating to severe diarrhea
watery diarrhea, abd. bloating and pain, flatulence, nausea
Labs: lactose intolerance
hydrogen breath test
dietary elimination
SSX: tropical sprue
acute phase: diarrhea with fever and malaise
chronic: diarrhea, nausea, vomiting, abd. cramps….
PE: tropical sprue
vitamin deficiency signs
glossitis, stomatitis, cheilosis, cutaneous hyperpigmentation…
Work-up: tropical sprue
no definitive markers exist
60% pt.s have megaloblastic anemia
Where is prevalence of celiac dz highest?
people with GI sxs and a first degree relative with celiac
any age
females
Who might you consider to screen for celiac dz?
those with unexplained iron deficiency, early onset osteopenia, unexplained epilepsy, failure to thrive, poor glucose control, chronic diarrhea, infertility, miscarriage, elevated liver enzymes
Classic celiac sxs
diarrhea, steatorrhea, bloating, flatulence, vit/min deficiencies
How might infants present with celiac disease beyond the classic sxs?
failure to thrive anorexia vomiting psychomotor impairment hypoproteinemia acidosis
What atypical sxs may present with celiac dz in adulthood?
aphthous ulcers dyspepsia fatigue infertility neuropsychiatric bone pain weakness dermatitis
Work-up: celiac disease
CBC CMP Serology: Serum IgA quantitation, Serum IgA anti-endomysial Abs IgA tissue transglutaminase Abs Deamidated gliadin peptide IgA and IgA
Procedures for celiac dz
small bowel biopsy is confirmatory
4 DDX for celiac dz
crohn's giardia HIV IBS intestinal lymphoma
What are some differences in sxs of IgE and non-IgE mediated food allergies
IgE: variable, dermatologic, ophthalmologic, GI, CV (multisystem) n/v, cramping, diarrhea, pruritis, edema
non-IgE: chronic vomiting, diarrhea, reflux, failure to thrive, atopic derm
