week 11- lower GI Flashcards
• what are food allergies and adverse food reactions?
o Need good hx to identify food
o immunologic/allergic (IgE or non-IgE mediated) or non-immunologic reactions
o healthy gut immune: luminal barriers, GALT, Peyer’s patches, normal flora, block intact proteins, ags from entering system
o allergic rxn: driven by Th2-skewed response and cytokine release
• what are hypothesized causes of food allergies/rxns?
o Better infant hygiene → less microbial exposure
o ↓Omega-3, ↑Omega-6 fats in diet
o Processed foods: ↓antioxidants, altered protein configuration
• What are IgE-mediated food allergies?
o rapid onset (mins- 2 hrs of ingestion), mast cells or basophils release cytokines
o common: cow’s milk, egg, soy, wheat, tree nuts, peanuts, shellfish
o ssx: variable, dermato, ophthalmo, GI, resp, CV, neuro, N/V, cramping, diarrhea, flushing, pruritis, edema, syncope
• what are non-IgE mediated food allergies?
o subacute/chronic sx in GI or skin
o Often type III or IV hypersensitivity rxns
o Delayed onset, hrs-days after ingest
o Ssx: chronic vomiting and diarrhea, reflux, failure to thrive, atopic dermatitis
• What testing is done for food allergies?
o Skin tests (IgE), RAST (IgE, blood, radioallergosorbent test), elimination/challenge diet, food diary
• What are Non-immunologic adverse food reactions?
o very common
o Anatomic conditions, malabsorption syndromes, GERD, toxic rxns (seafood, food poisoning), agents (eg caffeine, tyramine-containing foods, alcohol, MSG, preservatives), contaminants, food aversions/phobias
• What are the types of tumors of the bowel?
o SI tumors
o Polyps of colon, rectum
o Colorectal CA (CRC)
o Anorectal CA
• What are the SI tumors?
o Benign: leiomyoma, lipoma, neuromas → distention, abd pain, bleeding, obstruction
o Serious: Adenocarcinoma (st in Crohn’s), Lymphoma (st in Celiac), Carcinoid, Kaposi’s sarcoma
• What are polyps of the colon and rectum?
o small sessile or pedunculated mass of, into lumen
o non-neoplastic (benign), adenomas (CA precursor), polyposis syndromes
• what are non-neoplastic polyps of colon?
o Hyperplastic, usu < 0.5 cm, 90% of all epithelial polyps
o also hamartomas, pseudopolyps, lipomas
• what are adenoma polyps of colon?
o ~10%
o Histological types: tubular, tubulo-villous, villous
o Risk of malignant potential related to size and histological type
o < 1.5 cm tubular adenoma 2% risk
o 3 cm villous adenoma 35% risk
• What are polyposis syndromes? 2 types?
o familial inherited (AD) or nonfamilial.
o Familial Adenomatous Polyposis: rare, childhood, entire colon; many asx, some rectal bleeding; 100% HAVE CARCINOMA BY 40! (colostomy done prophylactically); st extracolonic ssx: osteomas of skull or mandible, sebaceous cysts, adenomas in other parts of GI
o Peutz-Jeghers Syndrome: AD, hamartomas in stomach, SI, colon; cells mature but don’t reproduce= self limiting), ↓malignancy; mucocutaneous pigmentation (buccal, lips, soles, dorsal hand)
• What is etio/risks of CR polyps?
o exposure to cigarette smoke
o alcoholism
o UC ↑ risk, and w primary relatives w UC
o acromegaly 3x risk
o skin tags, 10-77% incidence (sycotic miasm??)
o pelvic radiation 2-4x incidence
• what are ssx of CR polyps? Dx?
o 2/3 > 65 have at least one adenomatous polyp (< 1 cm diameter), often mult, usu rectum, sigmoid colon
o Asx or bleeding (mb occult), abdl pain (rare) dt partial obstruction, change in bowel habits
o watery diarrhea w large villous adenomas
o dx: colonoscopy, also seen on barium x-ray
• what is incidence of CRC?
o very common CA (#3 after lung, prostate/breast); 2nd mc cause of CA-related deaths in developed countries
o ↑ in North America, Western Europe, Australia, ↓ in Japan, South America, Africa
o F > colon, M > rectum
• What is etio and risk factors for CRC?
o ↓ fiber, ↑ fat and animal protein, esp beef w prolonged transit time, intestinal flora produce carcinogens
o transformation of adenomatous polyp
o > 40
o IBD: UC 30% after 25 yrs, Crohns 4-10x
o familial polyposis (100%)
o FHx 1 relative w CRC 3x
o PHx breast, female genital CA
o acromegaly: excessive GH → pituitary do
o hamartoma (benign growth of tissue, self-limiting)
o septicemia dt Streptococcus bovis infx, 55%
o smoking/alcohol
• what are ssx of CRC?
o Early: asx many years (occult blood +)
o R, ascending and cecum: lg before sxs; fatigue, SOB, angina dt microcytic, hypochromic anemia; vague abd discomfort, palpable mass later, obstruction uncommon, ulcerative, occult blood
o L, descending and sigmoid: encircles colon, diarrhea, constipation, alt tenesmus wi BM, obstruction pn late, hematochezia or occult blood (IDA)
o Rectum: gross blood in stool
o Advanced: wt loss, anorexia, malaise, jaundice, ascites, HM, SC LA (virchow)
• What is work-up for CRC? Ddx?
o Screen: fecal occult blood, colonoscopy, CT colonography, urine indican metabolites of undigested protein
o Dx labs: hemoccult blood, CBC (anemia), liver enz, Carcinoembryonic antigen (CEA) ↑ in 70%, but not specific
o Dx imag: sigmoidoscopy (rigid or flexible), double-contrast barium enema, colonoscopy
o Ddx: diverticula, ischemic colitis, IBD, benign polyps, hemorrhoids
• What is anorectal CA?
o adenocarcinoma (mc), SCC, BCC, Lymphoma o risks: HPV, fistulas, leukoplakia, lymphogranuloma venereum, condyloma accuminata, anal intercourse
• what are the anorectal dos?
o Hemorrhoids o Anal fissure o Anorectal abscess/fistula o Pruritis ani o Proctalgia fugax o Proctitis o Pilonidal dz
• What are hemorrhoids? Risk factors?
o clusters of vascular tissue (eg arterioles, venules, AV connections), smooth muscle (eg Treitz muscle), overlying mucosa
o usu inflammation, thrombosis, bleeding
o ~50% of adults. Peaks 45-65. M=F
o Diarrhea, preg, childbirth, ↑intra-abdominal P, heavy lifting, long sit/stand, valsalva (cough, straining), anal intercourse, ↓ fiber, ↑fat diet
• What are ssx of internal hemorrhoids?
o =above dentate line, no sensory innervation): MC, pnless bleeding w BM, prolapse → perianal itching (pruritus ani), irritation, mb pain, spasm of sphincter complex around hemorrhoids
o acute pn if incarcerated, strangulated: sphincter complex spasm → concomitant external thrombosis → acute cutaneous pain = emergent tx
• What are ssx of external hemorrhoids?
o =below dentate line, have sensory innervation; 2 modes of sxs
o acute thrombosis of underlying external hemorrhoidal vein: usu dt specific event (physical exertion, straining w constipation, bout of diarrhea, change in diet). Painful, lasts 7-14 d, resolves. stretched anoderm persists as excess skin or skin tags. st erode skin → bleeding. Recurrence~40-50% at same site
o cause trouble w hygiene w development of skin tags
• what PE is done for hemorrhoids?
o visualization of external hemorrhoids (tender, bluish, spherical masses at anal verge)
o skin tags
o DRE: internal hemorroids non-tender
o Anoscopy: pink/blue friable swellings of mucosa
• What is an anal fissure? Etio?
o acute linear midline tear in anal canal from dentate line to anal verge
o 87% w chronic are 20-60
o in children may indicate sexual abuse
o etio: hard stool, chronic diarrhea, 10% dt childbirth, excess laxatives, anal intercourse, DRE, hx syphilis/STDs, TB, leukemia, Crohn’s (30-50%), anal surgery, HIV
• what are ssx of anal fissure?
o rectal pain (burning, cutting, tearing o Painful defecation; spasm of anus o bloody stool: bright-red blood on surface, st on toilet paper after wiping o mucoid d/c o pruritus
• what is ddx of anal fissure?
o Diverticular dz, IBD, Peds: GI bleed, Pilonidal cyst/sinus
o Herpes simplex, HIV/AIDS, Syphilis
o Hiradenitis suppurative (skin dz), proctitis
o Foreign body, Peds: sexual abuse
• What is anorectal abscess/fistula? Etio?
o Cryptoglandular dz: Obstruction of anal glands at dentate line → infx
o Chronic →fistula, connects anal canal w perianal external opening
o Etio: Crohn’s, leukemia, diverticulitis, foreign body rxns, actinomycosis, chlamydia, lymphogranuloma venereum (chlamydia type), syphilis, TB, radiation, HIV
• What are ssx of anorectal abscess/fistula?
o throbbing, constant perianal pn, edema, erythema, recurrent malodorous perianal drainage, pruritus, recurrent abscesses, fever
o pain st resolves spontaneously w reopening of a tract or formation of new outflow tract
o pain w sit, move, defecate, cough
• what is pruritis ani? Etio?
o anal and perianal itching
o allergy: foods, soap, ointments
o irritants in foods: spices, hot sauces, peppers
o frequent diarrhea, loose stools, incontinence
o parasites: pinworms (Enterobius vermicularis) (“scotch tape test”)
o fungi, bacteria, yeast
o hygiene: poor, or excess soap
o warmth and hyperhidrosis: tight body stocking, jockey shorts, climate, obesity
o dermato dos: psoriasis, atopic dermatitis
o oral abx: esp tetracycline
o systemic dz: DM, Crohn’s, liver dz, CA
o sexual abuse
o hemorrhoids, skin tags, fissure, fistula
• what is proctalgia fugax? Risk factors?
o (fugax = fugitive/fleeting)
o benign anorectal-pain syndrome, unknown etio, 8-18% pop
o can cause severe distress
o spasm of levator ani and coccygeal muscles
o risk: ↓fiber diet, IBS. >50% 30–60. ↓ >45
• what are ssx of proctalgia fugax? PE?
o recurrent episodes of sudden, severe cramping pain localized to anus or lower rectum; lasts secs to >30 mins, resolves completely
o often in middle night, awaken pt
o entirely pain-free bw episodes
o infrequent, <5/yr in 51%
o may come in clusters (daily) then abate for long periods
o assoc: back pain, prostatitis, depression
o PE: Pain mb reproduced w DRE
• What is proctitis?
o inflammatory change of rectum (within 15 cm of dentate/pectinate line)
o similar to procto-sigmoiditis, but not necessarily assoc w proximal extension into colon, usu does not evolve into UC (may in a few pts)
• what is etio of proctitis?
o inflammatory or infectious
o amebiasis, C trachomatis, N gonorrhoeae, syphilis (secondary), lymphogranuloma venereum
o papillomavirus, HSV 1 (10%) and 2 (90%)
o Crohn’s, ischemia, anal intercourse
o immunodeficiency dos, radiation tx
o toxins, vasculitis
• what are ssx of proctitis? Ddx?
o Mucopurulent dc; Rectal pain, bleeding on defecation; tenesmus, often constipation
o Ddx: anal fistula/fissure, chancroid, diverticular dz, foreign bodies, gonorrhea, HIV/AIDS, herpes Simplex, IBD, syphilis, vulvovaginitis
• What is pilonidal dz?
o Chronic draining sinus from cyst, possible abscess formation in sacrococcygeal area
o Asx, or painful when infected
