Clin - Melena and Hematochezia Flashcards
compare ddx for lower GI bleed in patients under and over 50
under 50:
- infectious colitis
- anorectal dz (anal fissures, hemorrhoids)
- IBD
- meckel diveritculum
over 50:
- malignancy
- diverticulosis
- angiectasias
- ischemic colitis
which is more likely to present with shock or orthostasis and require transfusions: UGIB or LGIB
UGIB
serious lower GI bleeding is more common in _____
older men
notable PMH for pts with lower GI bleeds
1) prior GI bleeding
2) hx of aortic stenosis, renal dz
3) liver dz (portal HTN?)
4) IBD or diverticular dz
5) ETOH abuse
notable prior medications in pts with lower GI bleeds
1) NSAIDS, anticoags
2) meds w/ iron or bismuth (make stool darker)
3) liquid meds w/ red dye and certain red foods
diagnostic tests in pts with lower GI bleeds
1) colonoscopy in stable pts
2) anoscopy
3) EGD or sigmoidoscopy in massive active bleeding
tx/management for pts with lower or upper GI bleeds
1) 2 large bore IVs
2) fluid bolus if signs of shock
3) blood transfusion if indicated
4) CBC, INR/Pt/Ptt
what is diverticulosis
herniations or saclike protrusions of mucosa through muscularis at points of nutrient artery penetration
- most common cause of major lower GI bleed
- most common in sigmoid colon
most common cause of major lower GI bleeds
diverticulosis
what CT disorders are associated w/ diverticulosis
1) ehler’s-danlos
2) marfan
3) scleroderma
sx of diverticulosis
- painless hematochezia
- no abd pain
diagnostic test for diverticulosis
- colonoscopy in stable pts once bleeding subsides
- CBC, chemistry, vital signs
management for uncomplicated diverticulosis
high fiber diet, psyllium extract, anticholinergics
management for diverticulosis w/ hemorrhage
- two large bore IVs
- fluid bolus if signs of shock
- blood transfusion if indicated
CARD15/NOD2 gene is related to what dz process
crohn’s
crypt abscesses are associated with what dz process
UC
which IBD do oral contraceptives increase risk for
crohn’s
relationship between smoking and UC and CD
UC: may prevent dz
CD: may cause dz
what events in the first year of life can affect risk for UC and CD
antibiotic use: 2.9x increased risk of IBD
breastfeeding: can be protective
what infections increase risk for IBD
salmonella, shigella, campylobacter, C. diff
what dietary factors can increase risk for IBD
high animal protein, sugars, sweets, oils, fish, high omega 6 and low omega 3
“string sign” on barium enema
crohn’s (narrowing from inflammation or stricture)
“lead pipe” colon on barium enema
UC (loss of haustra)
what stool studies should you order when suspecting IBD
- stool cultures
- fecal lactoferrin
- fecal calprotectin
anti-neutrophilic cytoplasmic antibodies (ANCA) are associated with what dz process
UC
antibodies to saccharomyces cerevisiae (ASCA) are associated with what dz process
CD
labs to order when suspecting crohn’s
CBC, CRP, chemistry, ASCA, stool studies for infection and for fecal calprotectin
imaging to order when suspecting crohn’s
- CT or MRI enterography
- CT w/ or w/o contrast
- pelvic MRI (perianal fissures)
- EGD
- colonoscopy
- barium enema
9 possible crohn dz fistulas
- colovesical
- enterovesical
- colovaginal
- enterovaginal
- enterocolonic
- colocutaneous
- enterocutaneous
- entero-enteral
- anorectal
compare diarrhea b/w UC and CD
CD: with or without blood
UC: bloody w/ mucus
sx of ischemic colitis
sudden onset of cramping in the LLQ with desire to defecate and passage of blood or bloody diarrhea
demographic ischemic colitis
1) older patients w/ atherosclerotic dz
2) younger patients on vaso-occlusive recreational drugs (cocaine)
3) pts w/ vasculitis, coag disorders, estrogen therapy, long distance running
most common area for ischemic colitis
watershed area of splenic flexure
imaging results in ischemic colitis
abd x-ray shows thumb-printing
sigmoidoscopy shows submucosal hemorrhage, friability, ulcerations
thumb-printing on x-ray
ischemic colitis or acute mesenteric ischemia
sx acute mesenteric ischemia
1) periumbilical pain out of proportion to tenderness
2) food fear (abd pain worsens w/ eating)
3) N/V, distention, GI bleeding
diagnostic study of choice for acute mesenteric ischemia
CT angiography
tx/management for acute mesenteric ischemia
- laparotomy to restore intestinal blood flow
- postoperative anticoags
sx of hemorrhoids
bright red blood per rectum - usually only drops on tissue or in toilet
tx hemorrhoids
bulk laxatives and stool softeners, sitz baths, witch hazel compresses, analgesics
complications of hemorrhoids
thrombosed external hemorrhoid
- acute onset of very painful, tense, bluish perianal nodule covered with skin
what are anal fissures
linear or rocket-shaped ulcers less than 5mm in length
causes of anal fissures
trauma to anal canal during defecation or by straining from constipation
sx anal fissures
severe, tearing pain during defecation following by throbbing discomfort
- may have mild hematochezia w/ blood in stool or on toilet paper
how to diagnose anal fissures
seen on external anal inspection or anoscopy
tx for anal fissures
- fiber supplements and sitz baths
- topical anesthetics
- internal anal sphincterotomy in some cases
causes and sx of proctitis
organisms causing inflammation of anal and rectal mucosa
MOST are sexually transmitted
anorectal discomfort, tenesmus, constipation, mucus or bloody discharge
how to diagnose a neisseria gonorrhoeae anorectal infection
rectal swab during anoscopy
cultures taken from pharynx and urethra in MEN
cultures taken from pharynx and cervix in WOMEN
how to diagnose a treponema pallidum anorectal infection
dark-field microscopy or fluorescent antibody testing
VDRL or RPR test is positive in 75% primary cases and 99% secondary cases
how to diagnose a chlamydia trachomatis anorectal infection
serology, culture, or PCR-based testing or rectal discharge or rectal biopsy
complication and its sx of anorectal chlamydia infection
lymphogranuloma venereum
proctocolitis w/ fever and bloody diarrhea, painful perianal ulcers, anorectal strictures and ulcerations, fistulas, and inguinal adenopathy
most common cause of anorectal infection
HSV 2
how to diagnose an HSV2 anorectal infection
viral culture, PCR, or antigen detection assays of vesicular fluid
when suspecting a condylomata acuminata anorectal infection what must you distinguish the warts from
warts must be distinguished from condyloma lata (secondary syphilis) or anal cancer
what infectious agent is associated with anal cancer
HPV
etiology of perianal pruritis
poor anal hygiene associated w/ fistulas, fissures, prolapsed hemorrhoids, skin tags, minor incontinence
mutation in MUTYH gene
familial adenomatous polyposis
treatment/management for FAP
complete proctocolectomy with ileoanal anastomosis recommended before age 20
DNA base-pair mismatches in genes MLH1, MSH2, MSH6, PMS2
lynch syndrome (HNPCC)
treatment/management in all patients and just women with HNPCC
all pts: subtotal colectomy w/ ileorectal anastomosis
women: prophylactic hysterectomy and oophrectomy at age 40 or once they have finished childbearing
how to diagnose lynch syndrome (HNPCC)
genetic testing
sx and diagnostic test for nonfamilial adenomatous and serrated polyps
most are completely asymptomatic with maybe intermittent hematochezia from ulcerated polyps
colonoscopy
sx of PTEN multiple hamartoma syndrome (Cowden dz)
hamartomatous polyps and lipomas throughout the GI tract
trichilemmomas and cerebellar lesions
regular screening recommendations and above average risk screening recommendations for colorectal cancer
regular: start at age 45 through age 75, ages 76-85 based on preference, no need after 85
above average: every 5 years beginning at age 40 or 10 years before age of youngest affected relative
most colon cancers arise from _____
adenomatous polyps
there is a high prevalence of colon cancers in pts with what infectious organism
streptococcus bovis
early diagnosis of colon cancer is aided by screening asymptomatic pts with _____
fecal occult blood testing
diagnostic testing for colon cancer
1) fecal occult blood testing
2) sigmoidoscope (reaches 60cm)
3) air contrast barium enema (will diagnose 85% cancers
not within reach of sigmoidoscope)
4) colonoscopy (most specific)
sx of angioectasia (angiodysplasias)
painless bleeding ranging from melena or hematochezia to occult blood loss
demographic of angioectasia
pts over 70 and those with chronic renal failure or aortic stenosis
diagnostic studies for angioectasia
1) CBC w/ iron studies
2) endoscopic workup
most useful method of diagnosis for meckel’s diverticulum
technetium 99 scan
