week 7- lower GI

Question 1

• What is acute intestinal perforation? Causes?

Answer 1

o emergency!
o Any part of GI, spill gastric, intestinal contents into abd cavity
o General causes: blunt or penetrating trauma, foreign bodies
o in SI: duodenal ulcer, corrosives, strangulation of bowel, acute appendicitis
o colon: obstruction, diverticulitis, IBD, toxic megacolon

Question 2

• what are ssx of acute intestinal perforation? PE? Work-up?

Answer 2

o Ssx: sudden, severe general abd pn, tender, signs shock, N/V, anorexia
o PE: quiet to absent BS; peritoneal (guarding, rigidity)
o ***Note: in pts w underlying GI do, looks like “worsening” (more gradual, localized pn)
o Work-up: free air seen (usu SI) on abd xray or CT

Question 3

• What is gastroenteritis? Hx?

Answer 3

o inflam lining of stomach, SI, LI (mc dt infx)
o usu self-limiting, mb serious in young, elderly, immunocompromised
o hx: ingest potentially contaminated food, water, travel, contact w similarly ill person, meds (eg abx)

Question 4

• what are normal intestinal microflora?

Answer 4

o GI has 500 bacteria spp
o Stomach and proximal SI: few bacteria dt acidity
o Jejunum: lactobacilli, enterococci, gram (+) aerobes, facultative anaerobes
o Terminal ileum: enterobacteria, coliforms
o Colon: anaerobes: bacteriodes, lactobacillus, clostridium, bifidobacterium

Question 5

• What are general ssx of gastroenteritis? PE? Work-up?

Answer 5

o Vary. Sudden N/V, anorexia, abd cramps, diarrhea. mb malaise, myalgia
o PE: distension, tender, borborymi
o Wu: Stool test (hemoccult, fecal WBCs, O&P, culture), Rapid enzyme assays (viral ags, Shiga toxin), CBC, CMP (hypokalemia; vomiting → metabolic alkalosis, diarrhea → acidosis)

Question 6

• What is viral gastroenteritis?

Answer 6

o 30-40% infx diarrhea in US
o Viruses infect enterocytes in SI villi → transudate of fluid/salt into lumen
o →watery diarrhea, rare blood or mucus

Question 7

• What is rotavirus GE?

Answer 7

o Mc infx diarrhea worldwide. 33% hospitalizations, 20% of GE
o Highly contagious: fecal-oral, peaks in winter
o Severe, dehydrating diarrhea in kids (peaks 3-15 mos). Mild in adults
o Ssx: vomit, fever >102°F. sxs can last 5-7 d

Question 8

• What is norovirus GE? Astrovirus?

Answer 8

o N: older children and adults, year-round incidence, mb epidemic w water and food-borne outbreaks, highly contagious; acute onset vomit, abd cramps, diarrhea, fever, HA; lasts 1-2 d
o A: infants and young kids, winter months, fecal-oral, ssx similar to rotavirus

Question 9

• What is enteric adenovirus GE? Other?

Answer 9

o E: kids <2, year-round/summer, fecal-oral. Diarrhea 1-2 wks → mild
o In immunocompromised, CMV and enterovirus can cause gastroenteritis

Question 10

• How does exotoxin cause GE?

Answer 10

o Bacterial toxin → environment, pre-formed toxin ingested in contaminated food → N/V, watery diarrhea in 12hr of ingestion, minimal systemic sx (except botulinum), relief in 36 hrs; Stools have no blood or WBCs

Question 11

• Describe GE caused byStaphylococcus aureus:

Answer 11

o MC food poisoning, dt food-handlers; Custard, milk products, potato salad, salad dressing, coleslaw, processed meat/fish at room temp
o Ssx: sudden severe vomit 2-6 hr after ingesting, explosive diarrhea, abd. cramps, rare fever; last 3-6 hours, usu complete recovery

Question 12

• Describe GE dt Bacillus cereus:

Answer 12

o spore-forming, in soil, survive high heat of cooking; usu contaminated rice or meat
o 2 distinct syndromes:
o Emesis: 2-6 hrs after ingestion, severe vomit, abd. pain w or wo diarrhea; no fever, no systemic sxs
o Diarrhea: 8-16 hrs; foul smelling, profuse w nausea, abd pain, tenesmus
o resolves in 12-24 hours

Question 13

• describe GE dt Clostridium perfringens:

Answer 13

o spore-forming anaerobe, in feces, soil, air, water; most toxin synthesized before ingestion, additional produced in GI; beef, beef products, poultry; food inadequately pre-cooked, reheated before served
o ssx: watery diarrhea, foul-smelling w severe, crampy abd. pn, 8-16 hr after ingestion
o self-limited, resolves in 24-36 hrs

Question 14

• describe GE dt Clostridium botulinum?

Answer 14

o 3-exotoxin types (A, B, E); 1/3 deaths from food borne dz.
o A, B: improperly prepared home-canned non-acidic food (string beans, corn, mushroom, spinach, olives, beets, asparagus)
o E: smoked freshwater fish
o Boiling in water for 15 min can inactivate exotoxin
o Ssx: incubation 4 hr- 8 d after ingesting
o phase 1: vague, short period fatigue, N/V, abd cramps, diarrhea
o 2: visual, diplopia, ↓ acuity, PERRLA, ptosis
o 3: neuro, descending weakness or paralysis, dysarthria, dysphagia, weakness of trunk and extremities, sensorium unaffected, norm or ↓ temp; blood, urine, CSF normal
o 65% mortality 2-9 d after ingestion; with tx., < 10%- supportive to prevent respiratory impairment
o Ddx: polio, encephalitis, M gravis, curare, belladonna poisoning

Question 15

• How does enterotoxin cause GE?

Answer 15

o Bacterial cytotoxin, specific for mucous membrane of intestine (in vivo). ↓intestinal absorption, ↑secretion water, electrolytes →watery diarrhea

Question 16

• Describe GE dt cholera and non-cholera vibrio:

Answer 16

o endemic in Asia, fecal contaminated water or food, saltwater crabs and freshwater shrimp. incubation 1-3 d after ingestion
o ssx: sudden, painless, profuse, large volume, watery diarrhea, no blood or mucus, usu no fever vomit tenesmus
o water and electrolyte loss → thirst, oliguria, muscle cramps, weakness, cold, cyanotic skin, dehydration, hypotension, tachycardia
o recover in 7-10 w rehydration; fatal in > 50% untx severe cases

Question 17

• describe GE dt Enterotoxigenic Escherichia coli:

Answer 17

o diarrhea dt tissue invasion or enterotoxin
o fecal/oral, contaminated water or food, traveler’s pathogen
o Incubation: 1-3 days
o SSX: Profuse, watery diarrhea, lasts 3-5 days

Question 18

• Describe GE dt Clostridium difficile ( “C diff”)

Answer 18

o overgrowth of intrinsic organisms (post antibiotic) or infx by external source (soil, water, pets) →pseudomembranous colitis; common nosocomial dz, or iatrogenic after abx
o Ssx: watery diarrhea, cramping abd pain. N/V rare.

Question 19

• What is toxin megacolon?

Answer 19

o Complication of C diff → pseudomembranous colitis
o Other possible causes: UC, Crohn’s, Entamoeba histolytica, Yersinia infx
o Dilated colon w fever, abd pain, tachycardia
o PE: tender abdomen, absent BS
o Work-up: ↑ WBC, distended bowel on xray. Colonoscopy is contraindicated (risk of perforation, sepsis, septic shock)

Question 20

• What is mucosal invasion by microorganisms?

Answer 20

o by ingested organism → microscopic ulceration, bleeding, exudates, secretion of electrolytes and water
o Stool has WBCs, RBCs. mb gross bloody or watery diarrhea
o watery: > 1 L/d; usu no fever, h/a, myalgia, arthralgia
o bloody: usu abd pn, tenesmus, N/V, fever, malaise
o fever and prostration common

Question 21

• describe GE dt salmonella mucosal invasion:

Answer 21

o undercooked chicken or eggs, unpasteurized milk, contact w reptiles
o requires large inoculum to produce infx → exudative diarrhea; (also enterotoxin causes secretory diarrhea)
o ssx: watery diarrhea mc, mb bloody, h/a, malaise, N/V, abd. pain 6-48 hr after ingestion, may have fever
o usu self-limited to 7 days

Question 22

• describe GE dt Campylobacter jejuni and fetus mucosal invasion:

Answer 22

o mc bacterial cause of bloody diarrhea in US; pork, lamb, beef, milk products, water, infx pets
o incubation period 1-7 d
o ssx: mb prodrome of h/a, myalgia, malaise for 12-24 hr, then severe abd pain, ↑ fever, profuse watery diarrhea, then bloody diarrhea
o usu self-limited to 7-10 d

Question 23

• describe GE dt Shigella mucosal invasion:

Answer 23

o mc 6 mos - 5 yrs; food, water, milk; person to person; highly contagious with very small inoculum
o ssx: incubation 1-3 d; usu start low abd pn, diarrhea; fever in 50%; many have biphasic illness 1) fever, abd. pain, diarrhea; 3-5 days, 2) rectal burning, tenesmus, small volume bloody D
o Course: variable, kids resolves in 1-3 d; adults resolves in 1-7 d

Question 24

• describe GE dt Enterohemorrhagic Escherichia coli mucosal invasion:

Answer 24

o E. Coli 0157:H7 strain, produces Shiga toxin; bovine reservoir → beef, unpasteurized milk; fecal-oral toddlers diapers; usu affects several people (anyone else sick?)
o Ssx: acute onset severe abd cramps, watery diarrhea >16 hr after ingestion →bloody in 24 hr. 1-8 days if uncomplicated
o Comp in 5%: hemolytic-uremic syndrome (HUS) → hemolytic anemia, thrombocytopenia, acute renal failure
o thrombotic thrombocytopenic purpura (TTP) → HUS, fever, neurological deficits

Question 25

• describe GE dt Yersinia enterocolitica mucosal invasion:

Answer 25

o pork, unpasteurized milk, water o ssx: watery or bloody diarrhea and fever o May mimic appendicitis (RLQ pn, fever, vomit, leukocytosis) if infx in terminal ileum. AKA “acute ileitis”

Question 26

• What is Traveler’s Diarrhea?

Answer 26

o Aka Turista. GE dt organism endemic to locale visited (water, food) o Enterotoxigenic E coli mc, also norovirus o Ssx: N/V, borborygmi, abd pain/cramps, diarrhea, onset 12-72 hr after ingestion o Usu self-limiting, fever and bloody diarrhea suggest more serious dz

Question 27

• What are the parasitic infxs?

Answer 27

o Giardia lamblia o Cryptosporidium parvum o Entamoeba histolytica o Isospora, microsporidia, esp immunocompromised

Question 28

• Describe Giardia lamblia infx:

Answer 28

o Fecal-oral, water, person to person (daycare), traveling (esp low IgA, hypochlorhydria, malnutrition), ingestion of cysts which break down releasing organism o Ssx: inc 7 d, mb asx, mild watery diarrhea, abd bloating, cramps, flatulence for 1-3 wk, stools bulky, foul smelling o Course: mb self-limiting, chronic or recurrent dz (celiac-like lesion →lactose intolerance and malabsorption), fatigue, wt loss

Question 29

• Describe Cryptosporidium parvum infx:

Answer 29

o Common in HIV, immune-compromised, daycare; water, food, pets (esp cats) o Ssx: immune competent: profuse, watery diarrhea, anorexia, lo fever 5 days after ingestion; usu self-limited, lasts ~2wks o immune-compromised: mb chronic, watery diarrhea, up to 17/d, → dehydration

Question 30

• describe Entamoeba histolytica infx:

Answer 30

o endemic, travel, fecal-oral o institutionalized pt, HIV, AIDS, immune-compromised o cysts ingested, released → ulcers like IBD o ssx: mild: crampy, abd pn, intermittent diarrhea seere: bloody diarrhea, abd pn, tenesmus, fever, toxic megacolon

Question 31

• example of Fungal overgrowth:

Answer 31

o Basidiobolomycosis: SE US. Contaminated food or dirt

Question 32

• What is Drug and Chemical-related Gastroenteritis?

Answer 32

``` o Many agents and drugs → N/V, diarrhea o Pharmaceuticals: antacids, antibiotics, antihelminthics, colchicine, digoxin o Heavy metal poisoning o Laxative abuse o Poisonous mushrooms or plants ```

Question 33

• What is inflammatory bowel dz?

Answer 33

``` o Crohn’s and UC o Dt loss of tolerance to normal flora o Triggers: ↑intestinal permeability: tight junctions defect dt pathogens or inflammatory mediators (cytokines, chemokines, TNF, etc) o Imbalanced microflora o Psychological stress exacerbates ```

Question 34

• What is crohn’s dz?

Answer 34

o Aka Regional enteritis o Chronic transmural inflammation of colon, involves mesentery and regional LN. May involve entire GI tract from mouth to anus, rare: stomach, duodenum, esophagus; w “skip lesions” (normal) o Early mucosal involvement = longitudinal and transverse aphthous ulcers (cobblestone appearance). → deep fissures, sinuses and fistulas o Typical pattern is intermittent exacerbations and periods of remission, worse w stress

Question 35

• What is etio and risk factors for crohn’s?

Answer 35

o Unknown, genetic (assoc NOD2/CARD15), infx, immunologic, psychological… o Smoking o OCP, 2x risk o diet: diary, refined sugar, ↓ fiber, ↑ animal fat o dysbiosis, abx o inflamed appendectomy early in life

Question 36

• what is incidence of crohn’s?

Answer 36

o bimodal: peak 15-25, smaller peak 55-65 o 40 o 2-4X in Jewish, also higher in Caucasians o inc in higher socioeconomic group, Type A personality o F slightly >M

Question 37

• What are ssx of crohn’s? PE?

Answer 37

o RLQ pain, steady, localized, fatigue o Occult blood, in stool if colonic involvement (less common that UC) o Stool: formed, or loose if extensive colonic involvement or terminal ileum, o Fat malabsorption (steatorrhea) ↑ risk of gallstones, renal oxalate stones o 1/3 have perianal dz: fissures, fistulas, perianal abscess o PE: RLQ tenderness w assoc fullness or mass. Abdominal distention, fever, wt loss

Question 38

• What are the 4 sx patterns w crohn’s?

Answer 38

o inflammation: RLQ pn, tender, like appendicitis (esp in young) o obstruction: severe colic, abd distention, constipation, vomit o diffuse jejunoileitis: both inflam and obstruction → chronic debility o abd fistulas and abscesses: usu late, fever, painful masses, wasting

Question 39

• what are complications of Crohn’s?

Answer 39

o Intestinal obstruction. initial from edema and inflammation, esp ileum= reversible. → fibrosis → constipation, intractable obstruction from fixed luminal narrowing o Fistula → indolent abscess, malabsorption, cutaneous fistula, persistent UTI or pneumaturia (Enteroenteric, enterovesical, enterovaginal, enterocutaneous, retroperitoneal) o Perforation, hemorrhage: rare, dt thickened mucosa o ↑ risk SCC

Question 40

• What are labs for crohn’s? ddx?

Answer 40

o CBC: mild anemia, leukocytosis o ↑ESR, CRP (higher than in UC) o ↓serum iron, low vit B12 o + fecal lysozyme o Serology: ASCA (higher in Crohn’s), ANCA (higher in UC) o Ddx: IBS, lactose intolerance, Infx colitis, UC, appendicitis, diverticulitis, Carcinoma

Question 41

• What imaging is done for crohn’s?

Answer 41

o plain film, double-contrast barium enema exam o single-contrast upper GI series w SI follow-though barium x-ray: irregularity, nodularity, stiffness, thickening of terminal ileum, narrowed ileum lumen. Adv: string sign=marked stricture of ileum o CT and double-contrast SI. US and MRI as adjuncts if radiation an issue o Colonoscopy: "skip areas", "cobblestone appearance", longitudinal ulcers, rectal sparing, narrowing, fistulas o 50% have pathognomonic sarcoid-type epitheloid granulomas in intestinal wall, st involved mesenteric nodes

Question 42

• What is ulcerative colitis? Ulcerative proctitis?

Answer 42

o chronic, recurrent inflammatory, in colon or rectal mucosal layer o superficial ulceration of colon usu involves rectum (95%) o continuous involvement w any other portion of colon (NO skip areas) o UP: common, limited form, localized to rectum

Question 43

• What is etio and risk factors for UC?

Answer 43

o abn humoral and cell-mediated immunity, or generalized ↑ reactivity against intestinal bacterial ags. AI serum and mucosal abs vs intestinal epithelial cells o mb genetic (chrom 12 and 16), st pos FHx o mb environmental factors o diet: dairy, refined sugar, ↓ fiber, ↑ animal fat o smoking is negatively associated with ulcerative colitis (reverse in Crohn's)

Question 44

• what is incidence of UC?

Answer 44

o 2-4x in Jewish, also higher in Caucasians o M slightly >F o Bimodal: peak 15-25 and 55-65 yrs (or any age)

Question 45

• What are ssx of UC?

Answer 45

o Mild to severe o Cramping abd pain o Series of attacks of bloody diarrhea w asx intervals, insidious, ȑ urgency, low abd cramps, blood and mucus o if confined to recto-sigmoid area, stool mb normal, hard, dry w rectal d/c of mucus, RBCs, WBCs o if proximal, stools looser, 10-20/d w severe cramps, rectal tenesmus. Watery stools with pus, blood, mucus o Systemic: malaise, fever, anemia, wt loss

Question 46

• What are complications of UC? Px?

Answer 46

o Hemorrhage mc o Toxic megacolon: markedly distended colon (ballooning, >6 cm) w attenuated walls, severe: immediate danger of perforation o Mb dysplasia w ↑ risk colon cancer, inc 0.5-1% per year o Px: usu controlled w tx, lifelong exacerbations and remissions. Severe: surgery required

Question 47

• What are labs for UC?

Answer 47

o CBC: anemia, plt >350,000/mL o ↑ ESR, CRP o CMP: hypoalbuminemia, hypokalemia, hypomagnesemia, ↑alk phos o Stool: organisms (clostridium, salmonella, shigella, E coli, yersinia)

Question 48

• What imaging is done for UC?

Answer 48

o Plain abd film: colonic dilatation in severe suggests toxic megacolon. Mb perforation, obstruction, ileus o Barium enemas in mild case only. narrow, tubular, shortened colon w loss of haustral folds, pseudopolyps, small ulcers; "lead pipe" appearance (caution, barium enemas may precipitate toxic megacolon in severe cases) o flexible sigmoidoscopy: to dx o colonoscopy w bx: confirms Dx. see extent of dz, monitoring dz activity, watch for dysplasia, CA. risk perforation w severe dz

Question 49

• what are extra-intestinal manifestations of IBD (Crohn’s and UC)?

Answer 49

o Jts: Peripheral arthritis, Sacroiliitis, Ankylosing spondylitis o Skin: Erythema nodosum, Pyoderma gangrenosum o Eyes: Conjunctivitis, Iritis, Episcleritis o Liver: Fatty liver, Chronic active hepatitis, Pericholangitis, Sclerosing angitis, Bile duct carcinoma o Kidneys: Pyelonephritis, Urolithiasis o General: amyloidosis

Question 50

• What are extra-intestinal manifestations of Crohn’s?

Answer 50

``` o Cholelithiasis o Renal oxalate stones o Vitamin B12 def o Obstructive hydronephrosis o Aphthous ulcers ```

Question 51

• What is IBS?

Answer 51

o aka: Functional Dyspepsia, Spastic Colitis, Mucous Colitis o Dx of exclusion: over-dx, too hastily o Mc of all GI dos, up to 50% of pt to gastroenterologist o Counseling is helpful dt pt frustration w problem

Question 52

• What are (postulated) etio of IBS?

Answer 52

o Changes in GI motility (↑ luminal contractions, motor activity) o Hypersensitive visceral afferent nerves of gut o ↑ mast cell in gut, release local histamine o Colonic mm hyper-reactivity, neural, immune changes in S/L I may persist after gastroenteritis o abn glutamate activation of N-methyl-D-aspartate (NMDA) receptors, activate NOS, neurokinin receptors, induce calcitonin gene-related peptide o limbic system, emotion, autonomic response ↑ bowel motility, ↓gastric motility, more in ppl w IBS than normal o HPA. ↑ hypothalamic corticotropin-releasing factor (CRF) → alter motility, dt stress. CRF antagonists eliminate these changes. o SIBO in >50%, →bloating, gaseous distention. o Diet: ↓fiber, intolerance to lactose (diarrhea) and other sugars, (glucose intolerant, milk intolerant (casein) → congestion, bronchitis, asthma, mucus; gluten dd

Question 53

• What is AGA (2004) dx criteria or IBS?

Answer 53

o w/o red flag/alarm features or positive screening studies, additional dx test usu not necessary. RF: o sx onset > 50 o severe, unrelenting diarrhea o nocturnal sxs o unintentional weight loss o hematochezia o FHx organic GI dzs (IBD, celiac sprue, CA)

Question 54

• What are Rome III (2006) dx criteria for IBS?

Answer 54

o recurrent abd pn or discomfort at least 3 days/month in past 3 mos, assoc w 2+ of following: o relieved by defecation o onset assoc w change in stool frequency o onset assoc w change in stool form or appearance

Question 55

• what is clinical picture of IBS (chronicity of these sxs)?

Answer 55

o crampy abd pain o constipation, diarrhea, both, or alternating o ↑ colonic mucus production o flatulence, bloating/distention, nausea, anorexia o anxiety or depression o sxs related to stress o appearance of health

Question 56

• what is PE for IBS? Imaging?

Answer 56

o PE: Diffuse abd tenderness over colon, some areas worse, or fullness o x-ray: altered GI motility (spasm) o sigmoidoscopy: ↑mucus & spasm (or often nothing)

Question 57

• What labs are done for IBS?

Answer 57

o only to confirm other possible dx o CBC: anemia, inflammation, and infection o CMP: metabolic dos, r/o dehydration, electrolyte abn w diarrhea o hemoccult test o stool: complete GI health panel, lysozyme test normal o hydrogen breath tests for lactose intolerance o celiac testing

Question 58

• How can you confidently dx IBS?

Answer 58

o identify typical sxs, complete PE, and exclude alarm features. o if alarm features → more detailed work-up by predominant sxs o If tx not success → more extensive work-up o Celiac mb more prevalent in pts w suspected IBS o > 50 w IBS sxs → colonoscopy for CA screen

Question 59

• What is SIBO?

Answer 59

o ↑ # (>105/ml) or type of bacteria in SI → fermentation, inflammation, malabsorption. Ferm gas: hydrogen, methane o Enteric toxins produced: ammonia, D-lactic acidosis, bacterial endotoxin stimulating cytokine release o Mb Carb, protein, fat, B12 malabsorption o Organisms: Streptococci, Bacteriodes, Escherichia, Lactobacillus, Clostridium, Klebsiella

Question 60

• What can prevent SIBO?

Answer 60

o Antegrade peristalsis, gastric acid, bile, proteolytic enzymes, sIgA, intact ileocecal valve

Question 61

• What can cause SIBO?

Answer 61

o Anatomical anomalies: stricture, diverticula o Insufficient enzymes: hypochlorhydria, PPI use, ↓ bile salts o Abnormal motility: obstruction, DM, scleroderma, Crohn’s, radiation damage, opiates o Abnormal communication bw S/L I: fistula, defective valve o Other: immunocompromised, alcoholism, cirrhosis, pancreatitis

Question 62

• How may SIBO pt present? Hx. Ssx.

Answer 62

o Hx: transient improve after abx, worse w probiotic/prebiotic, worse w more fiber o Ssx: abd pain/cramps, borborygmus, eructation, flatulence, bloating, watery diarrhea may alt w constipation, dyspepsia, vomiting, heartburn, wt loss, steatorrhea, systemic sxs (HA, joint pain, fatigue, rosacea

Question 63

• What is PE for SIBO? Work-up?

Answer 63

o PE: surgical scar? Abd distention, succussion splash o CBC: macroscopic (B12) or microscopic anemia, ↓ ferritin o Glucose Breath Hydrogen analysis (H2) o C14-d-xylose breath test (Methane) o Jejunal aspirate during endoscopy

Question 64

• What is incidence of diverticular dz?

Answer 64

o ↑ w age: 70; 66% >85 | o Common in industrialized western society

Question 65

• What is diverticulosis?

Answer 65

o Sac-like outpouchings of colon sub/mucosa, mc in sigmoid o Dt factors that chronically ↑ intraluminal P: ↓ fiber, ↑ refined carbs o Usu asx (up to 70%) o Mb chronic or intermittent LLQ pain; often constipation o Mb rectal bleeding if erosion of mucosa o often observed on barium studies o 20% progresses to diverticulitis

Question 66

• what is diverticulitis?

Answer 66

o inflam 1+ diverticula, may → obstruction, perforation, abscess, fistula o may heal spontaneously, or enlarge and adhere to adjacent organs (bladder, vagina)

Question 67

• what is etio of diverticulosis/itis?

Answer 67

o ↓ fiber diet is highest risk factor → low-bulk stool → ↑intra-luminal P, form diverticula o Diet: ↑ fat and grain-fed beef o Genetic: Asians on R side, westerners usu L side o Aging → change in collagen structure o Colonic motility dos o Corticosteroids ↑ risk (not NSAIDs) o Colonic segmentation: non-propulsive contractions → isolated segments, little chambers w ↑ P o Defects in colonic wall strength

Question 68

• What are ssx of diverticulosis?

Answer 68

o Usu asx, mb recurrent LLQ tenderness, flatulence | o Mb hx painless rectal bleeding

Question 69

• What are ssx of diverticulitis?

Answer 69

o LLQ pn, steady, severe, deep o fever/chills, N/V o previous episodes dull, colicky, diffuse abd pain w flatulence, distention, change in BM (initially diverticulosis) o altered BM: diarrhea, constipation, tenesmus o Rectal bleeding: bright red or wine-colored stools; sudden onset, painless, w urge to defecate, usu massive, stop spontaneously

Question 70

• What are concominatnt and complication sxs of diverticulitis?

Answer 70

o Con: Dysuria, pyuria, urinary frequency if bladder or ureter irritated o Comp: if perforation or fistula o Pneumaturia (gas, “air” in urine), recurrent UTIs (colovesicular fistulas) o Feculent vaginal d/c (fistulas w uterus, vagina) o Severe, general abd pn, absent BS, fever (diffuse peritonitis) o Back or lower extremity pain (perforation)

Question 71

• What is PE for diverticulitis?

Answer 71

o Local abd tenderness, rebound tenderness, mb mass o Vitals, determine hemodynamic stability o ↓ fever o DRE: tenderness, color of stools, presence and extent of GI bleeding o Proctoscopic exam: mass in cul-de-sac

Question 72

• What is ddx for diverticulitis? Imaging?

Answer 72

o Ddx: hemorrhoids, anal fissures (pn w defecation); UTI, nephrolithiasis, obstruction, colon CA o Hx weight loss and mucus in stool indicates IBD o Image: sigmoidoscopy: narrowing and inflammation o barium x-ray hazardous in acute phase, may cause perforation

Question 73

• what is meckel’s diverticulum?

Answer 73

o Congenital bulge in distal ileum, remnant of omphalomesenteric duct o 2% pop, M>F o Usu asx, mb bleeding, obstruction, volvulus, intussusception, Acute mb like appendicitis

Question 74

• What are general ssx of malabsorption syndromes?

Answer 74

o Chronic diarrhea, steatorrhea, bloating, weight loss, amenorrhea o Macrocytic anemia (B12); microcytic anema (iron); easy bruising (Vit K and C); edema (protein); glossitis (B vits, iron); night blindness (vit A); bone pain/fractures (K, Mg, Ca, Vit D); muscle spasm (Ca, Mg); peripheral neuropathy (B 1,6,12)

Question 75

• What is malabsorption dt insufficient digestive elements?

Answer 75

o ↓ pancreatic/liver enzymes, bile salts, HCl | o post-surgical syndromes, biliary obstruction, cystic fibrosis, etc

Question 76

• what is Carbohydrate intolerance?

Answer 76

``` o Enzyme deficiencies mb congenital (rare), primary or secondary o Disaccharides (lactase, maltase, isomaltase, sucrase) normally split to monosaccharides by duodenal enterocytes’ enzymes o Lactose is dt Lactase deficiency o Def → ↑ osmotic load, watery diarrhea; fermentation → gas (H2,CO2, methane), flatulence, distention, abd pain ```

Question 77

• What is epidem of lactose intolerance?

Answer 77

o Acquired lactase def MC o US: 80% blacks and Hispanics; ~100% Asians, 25% N Euro whites o Worldwide: >75% mb lactose-deficient. Very common in Asian, South American, African

Question 78

• What is etio of lactose intolerance?

Answer 78

o Congential: AR (rare) o Primary: ↓ lactase, develops after childhood o Secondary (acquired): dt SI mucosal damage: acute gastroenteritis, ascariasis, carcinoid, celiac, chemo, Crohn’s, diabetic gastropathy, gastrinoma, giardiasis , HIV enteropathy, Kwashiorkor, radiation enteritis, tropical sprue, Whipple syndrome

Question 79

• What are ssx of lactase def?

Answer 79

o Varias, minor abd discomfort, bloating to severe diarrhea dt even small amounts of lactose o watery diarrhea, abd bloating and pain, flatulence, nausea, borborygmi

Question 80

• what labs are done for lactase deficiency? Ddx?

Answer 80

o hydrogen breath test: test of choice; lactose given after 8hr fast → collect expiration every 30 mins for 3 hrs. (+) = ↑ by > 20 ppm o dietary elimination: elim lactose foods → sxs resolve, return w reintroduction o ddx: IBS

Question 81

• what is tropical sprue? Etio?

Answer 81

o Residents, natives, prolonged visitors (>1mo) of Caribbean, S India, SE Asia; may improve after moving from tropics, or reappear years later (all dt vit/min deficiencies) o Etio: unknown, mb SI chronic infx by toxigenic coliform bacteria → folate, B12, iron malabsorption

Question 82

• What are ssx of tropical spru? PE? Ddx?

Answer 82

o acute phase: diarrheam fever, malaise o chronic phase: diarrhea, nausea, anorexia, abd cramps, steatorrhea, paresthesias o PE: vit def signs: glossitis, stomatitis, cheilosis, cutaneous hyperpigmentation, dry rough skin, abd distention, tenderness, edema (late), weight loss, dehydration o Ddx: GI infx (giardia, E hist, etc), intestinal lymphoma, AIDS, Celiac, pancreatitis

Question 83

• What is work-up for tropical sprue?

Answer 83

o No definitive marker exists o CBC: megaloblastic anemia (60%) o Stool: fecal fat > 6 g in 24 hrs is (+) fat malabsorption). Fatty stools usu observed when fat content >15 g o CMP: ↓serum protein, calcium, phosphorus, cholesterol, prothrombin, hypochlorhydria, check pancreatic function o D-Xylose absorption test: 25 g D-xylose orally. In well-hydrated patients with normal renal function (+) for mucosal malabsorption o 5-hr urine collection < 4 g o 1-hr serum collection < 20 mg/dL o Endoscopy: characteristic histology

Question 84

• What is celiac dz?

Answer 84

o Aka Celiac Sprue, Nontropical Sprue, Gluten Enteropathy o AI reaction to gluten proteins → mucosal damage; Environmental trigger = gluten; Autoantigen = tissue transglutaminase o Elimination of environmental trigger → complete resolution

Question 85

• What is epidemiology of celiac?

Answer 85

o ↑ in US and Europe; 0.5-1% pop. o Higher prev in pp w GI sxs (1/56), w first-degree relative w celiac (1/22) o ↓ in blacks, Hispanic, Asian o any age, but peaks in 40s o F:M, 2:1 o Genetics: Most all pts express human leukocyte antigen (HLA-DQ2 or HLA DQ8), facilitate immune response against gluten

Question 86

• What is pathophysiology of celiac?

Answer 86

o Gliadins and glutenins → CD4 cells w HLA-DQ → cytokines, B cell clones → lymphocyte-mediated destruction of proximal SI mucosal villi. o →vitamins, minerals, Ca+2, CHO, protein, fat malabsorption o T cells may react w TGT (principal component of endomysium autoantigen) →inflam events →characteristic celiac mucosal lesion

Question 87

• What are risk factors for celiac?

Answer 87

``` o Heredity o Type 1 DM o Early introduction of gluten in infant diet o Down’s o no breastfed o Chronic Fatigue Syn o Crohn’s o AI thyroid dz o Viral may trigger immunologic response (Adenovirus type 12 implicated) ```

Question 88

• What are some gluten containing foods?

Answer 88

o Wheat, wheat bran, Kamut, Spelt, triticale, bulgar, couscous, semolina o Barley, malt, malt extract o Rye o Some may not tolerate oats: React to avenin, or cross-contamination w gluten

Question 89

• When should you screen for celiac?

Answer 89

``` o Unexplained iron deficiency o early onset osteopenia o unexplained epilepsy o failure to thrive, o poor glucose control o chronic diarrhea o infertility o miscarriages o ↑ liver enz ```

Question 90

• What are ssx of celiac? In infants?

Answer 90

o Mb asx o Classic: diarrhea, steatorrhea, bloating, flatulence, vit/min def, o Atypical: extraintestinal signs: anemia, dermatitis herpetiformis, DM, aphthous stomatitis, neuro, osteopathy o <2: st more fulminant, chronic diarrhea (miserable, pale), abdominal distension, failure to thrive (↓weight, fat, hair thinning), anorexia, vomiting, psychomotor (muscle wasting), hypoproteinemia, acidosis

Question 91

• What are ssx of celiac in kids and adults?

Answer 91

``` o Kids (avg 4): diarrhea or constipation, anemia, short stature, osteoporosis, aphthous ulcers o Adults: st intestinal, diarrhea or constipation, anemia, aphthous ulcers, sore tongue and mouth (mouth ulcers, glossitis, stomatitis), dyspepsia, abd pain, bloating (weight loss), fatigue, infertility, neuropsychiatric (anxiety, depression), bone pain (osteoporosis), weakness (myopathy, neuropathy), dermatitis herpetiformis ```

Question 92

• What is lab work-up for celiac?

Answer 92

o CBC: Anemia (microcytic, hypochromic/normocytic, normochromic w RDW), Leukopenia o CMP: ↑ AST; ↓Albumin/plasma protein; ↓cholesterol (total, LDL, HDL), ↑ALP o Serology: Serum IgA, serum IgA a-endomysial Abs (IgA EMA) o IgA tTG (>100): mc sero test, cheap (ELISA) o Deamidated gliadin peptide (DGP) IgA and IgG: ↑sn &sp, esp in elderly who have normal standard tests

Question 93

• What are sn, sp, and method for the IgA celiac tests? What if there’s IgA deficiency?

Answer 93

``` o Gliadin (not used anymore): 57-100, 42-98, ELISA o Endomysial: 75-98, 96-100, Indirect IF o tGT: 98-100, 97-98, ELISA o def: in 8%, IgG EMA and tGT can be used ```

Question 94

• what procedures are done for celiac dx?

Answer 94

o ↓Bone mineral density o Dx by SI bx: need 4+ samples from jejunum and ileum, must eat gluten past 2-4+ wks o histo = characteristic villous atrophy

Question 95

• what is ddx of celiac?

Answer 95

``` o Anorexia nervosa, AI enteropathy o Crohn's o Giardiasis o HIV enteropathy, Hypogammaglobulinemia o Infx GE, Intestinal lymphoma, IBS, Ischemic enteritis o Lactose intolerance o Pancreatic insufficiency o SIBO, Soy protein intolerance o Tropical sprue, TB o Whipple's disease o ZES ```

Question 96

• What is non Non-Celiac Gluten Intolerance? Dx?

Answer 96

o mb similar sxs, WITHOUT villous atrophy o (-) IgA tTG o Bx (-) o (+) Gliadin Ab (IgA or IgG) (immune rxn to gluten) o Total IgA normal

Question 97

• What is whipple’s dz?

Answer 97

o rare, multisystem, dt bacterium Tropheryma whipplei | o diarrhea, weight loss, arthralgia, fever, malabsorption

Question 98

• what is short bowel syndrome?

Answer 98

o malabsorption from surgical bowel resection (esp jejunum)