GASTRO Flashcards
1
Q
test for CHO malabs
A
Xylose Absorption test
2
Q
fixed dose of xylose
A
25g d-xylose
3
Q
to visualize the GIT and allow collection of specimen
A
EGD or Esophagogastroduodenoscopy
4
Q
give Barium to the patient for visualization under xray
A
small bowel series
5
Q
visualize colon and terminal ileum with the use of barium
A
Barium enema
6
Q
endoscopic procedure, direct visualization of mucosa, identify lesions, take histological samples
A
Colonoscopy
7
Q
insert long tube in the small bowel, inflate with methyl-cellulose, take xray pic
A
enteroclysis small bowel enema
8
Q
patient ingests capsule which contains a camera, transmitter and a battery. it captures images as it passes through the GIT. reduce gap between UEE and Colonoscopy
A
video capsule endoscopy
9
Q
test for pancreatic insufficiency
A
secretin test (secretin - produced by upper duodenum and stimulates pancreas to release enzymes)
10
Q
test for B12 abs
A
schilling’s test
11
Q
test for bacterial overgrowth
A
breath test (lactulose, glucose-hydrogen), culture ((+) if bacterial colonies exceed 10’4)
12
Q
disorders that need biopsy
A
giardiasis, crohn’s, whipple’s/ celiac sprue
13
Q
s/s of malabs (common)
A
malnut, wt loss, diarrhea
14
Q
causes of malabs:
A
- Inadequate digestion
- Inadequate absorptive surface short bowel syndrome
- Bacterial overgrowth of SI
- Lymphatic obstruction
- Defects in mucosal structure and function
15
Q
inadeq digestion
A
- Liver and biliary tract disorders
a. liver cirrhosis
b. biliary tract obstruction
c. pancreatic insuff - Post Gastrectomy malabs
a. dec CCK and Secretin
b. inadeq mixing
c. stasis
d. loss of gastric reservoir function
16
Q
stim release of bile salts and pancreatic secretions
A
CCK and Secretin
17
Q
inadeq absorptive surface
A
- massive resection
- anti-obesity operation
- jejunal bypass
18
Q
resection of _____% of SI is well-tolerated
A
<40-50%
19
Q
bacterial overgrowth of SI
A
a. Bacterial deconjugation of bile salts
b. Bacterial production of toxins vs enterokinases (digestive enz)
c. Destruction of intestinal mucosa by bacterial toxins
d. Bacterial consumption of Vit B12
20
Q
part of SI that is sterile
A
proximal SI
21
Q
sterility of Proximal SI is d/t:
A
a. Acid milieu of stomach
Intestinal peristalsis
secretion of Ig in the lumen of SI (coproantibodies)
22
Q
plays a major role in maintaining the low level of bacteria
A
Peristalsis
23
Q
bile salts are effective when it is in _______ form
A
conjugated form
24
Q
conditions that poses risk of bacterial overgrowth in the SI:
A
- Chronic intestinal pseudoobstruction
- Tropical sprue
- Scleroderma
- Malabs in AIDS
25
decreased motility -> Stasis -> Bacterial overgrowth
Chronic Intestinal Pseudoobstruction
26
- affects visitors or residents of tropical countries
- chronic diarrhea, anemia, malnut, nutrient def
- theory: coliform org
Tropical sprue
27
- impaired intestinal motility, jejunal diverticulosis
- involve intestinal wall itself
Scleroderma
28
overgrowth of microorg d/t depressed immunity
Malabs in AIDS
29
lymphatic obstruction
1. Whipple's disease
2. Intestinal lymphoma
30
- rare dse
- arthralgia, ab pain, diarrhea, wt loss, impaired intestinal abs
whipple's dse
31
diagnostic tool for whipple's dse:
tissue dx, PCR
32
causative agent of whipple's dse
rod shaped microorganism identified by PCR
Trophyrema whipplei
33
DOC for whipple's = __________________
Alternative for whipple's = ______________
Trimethoprim sulfamethoxazole for 1 yr
Chloramphenicol
34
- increased lymphomatous cells
- resemble celiac sprue but w/ incomplete response to gluten free diet
- biopsy: total absence of vili, lesser degree of blunting, and shortening, infiltrated lamina propria
intestinal lymphoma
35
defects in mucosal structure and function
1. Inflammatory bowel disease
a. Crohn's
b. Regional enteritis
2. Biochemical and genetic abnormalities
a. Celiac sprue
36
mechanisms of IBD
a. Interruption of enterohepatic circulation
b. Deconjugation of bile salts
c. Impaired mucosal cell function
d. Inadeq absorptive cell function
e. Severe protein depletion
37
- destruction of ileum d/t resection, fistulas, impairing reabs of bile salts
- diffuse ulceration of SI
- short bowel syndrome
crohn's disease
38
- malabs, abnormal small bowel structure
- lack enz againts gluten/ intolerance to gluten
celiac sprue
39
gluten contains ______ w/c is toxic to intestinal cells
gliadin
40
pathogenetic theories of celiac sprue
a. Deficiency in specific mucosal peptidase (break down gluten to smaller products)
b. gluten may initiate immune reaction vs intestinal mucosa
c. viral etiology
41
diagnostic tools in celiac sprue
Jejunal biopsy
- in celiac, the vili are short and atrophied
Serology
- IgA anti gliadin ab
-IgA anti endomysial ab
42
water content of stool exceeds 200 ml per day
diarrhea
43
at the end of the day, the stool water content should not exceed ________
_______ is being rebsorbed
200 mL per day
8.8 L
44
driving force of water reabs from the lumen of intestine to the cells of intestine
Sodium
45
driving force for water secretion from cells of the intestine to the lumen
Chloride
46
- cAMP is generated from the cells via adenylate cyclase system
- conditions that stimulate adenylate cyclase system -> release chloride followed by water
cAMP Regulating Chloride Channel
47
vibrio ingested -> secrete toxin -> bind to specific receptor in the intestines -> trigger adenylate cyclase system -> ATP to cAMP -> opening of chloride gate -> chloride will be secreted followed by water
profuse rice watery stool
can loose approx 10L or water
cholera diarrhea
(Exogenous factor)
48
- endogenous opioid peptide
- decreases cAMP production -> close chloride gates -> inhibit secretion of chloride and water
enkephalins
(Endogenous factor affecting cAMP levels)
help decrease levels of cAMP
49
- feedback mechanism
- neutralizes the effects of enkephalins
enkephalinase / enkephalin inhibitors
50
- inhibit enkephalinase -> inhibit neutralization of enkephalins -> decrease cAMP -> inhib sec of chloride and water
enkephalinase inhibitor
can be considered as anti-diarrheal or anti-secretory
brand: Hidrasec, Acetorphan, Racecadotril
51
- inc daily stool wt >200g (most objective definition in research)
- inc stool frequency
- inc stool fluidity
Diarrhea
52
- inc defecation w/o inc in daily stool wt
e.g., IBS, hyperthyroidism
Pseudodiarrhea/Hyperdefecation
53
- invol release of rectal contents
- seen in px w/ spinal cord prob, elderly
Decal incontinence
54
classif of diarrhea
Acute = <7-14 days
Chronic = >4 weeks
Persistent = 2-3 weeks
55
most common cause of acute diarrhea ________
other causes _________
infectious agents
mg containing drugs, toxins, chemo
56
most common mode of trans of diarrhea
fecal oral route
57
pathophysio mech of Diarrhea
1. toxin prod
2. enteroadherance
3. mucosal invasion
4. systemic infection
58
toxin prod
a. preformed toxin
b. enterotoxin
c. cytotoxin
59
preformed toxin
- bacillus cereus, clostridum perfringens, staph au
- in cases of food poisoning
- IP: 6 hrs
60
enterotoxin
- aeromonas sp, ETEC, vibrio cholera
- open Cl gates -> profuse watery stool
61
cytotoxin
- clostridium deficile, EHC
- destroy cells of intestine -> bloody stools, ab pain, fever
62
enteroadherence
- crytosporidosis, helminthes, EAC, EPEC, giardia
- cling to the mucosa
63
mucosal invasion
a. minimal
b. variable
c. severe
64
minimal mucosal inv
- norwalk virus, rotavirus
65
variable mucosal inv
- vampylobacter sp, salmonella sp
66
severe mucosal inv
- entamoeba histolytica, EIEC, shigella sp
- can travel bloodstream and go to liver
67
systemic infection
legionella, listeria, measles, viral he, psittacosis, RMSF, TSS
68
diff dx of diarrhea
1. Drug-induced diarrhea (ex. coamox)
2. Acute diverticulitis
3. Intestinal ischemia
4. IBD
5. Pseudomembranous enterocolitis
69
drugs considered in symptomatic cases:
Shigella
C difficile
Traveler's diarrhea
EPEC EIEC DAEC
Typhoid
Cholera
Salmonella
Amoebiasis
Giardiasis
Ampicillin
Metronidazole
Ciprofloxacin
TMP SMX
Chloramphenicol
Tetracycline
Ampicillin
Metronidazole
Metronidazole
70
- persistent >4 weeks
- require evaluation
chronic diarrhea
71
pathophysiologic types of Chronic Diarrhea:
1. Inflammatory
2. Osmotic
3. Secretory
4. Dysmotility
5. Factitious
72
- fever, ab pain, tenesmus, blood pmns in stool
- inflammatory lesions in the mucosa
- inflam -> damage mucosa and submucosa
- e.g., IBD, radiation enterocolitis
inflammatory diarrhea
73
- unusually large amt of non-digested food
- inc osmotically active subs attracts water
- diarrhea improves with fasting
bulky fouls smelling
- e.g., lactase def
Osmotic diarrhea
74
- secretion>absorption
- watery diarrhea
- watery diarrhea persists w/ fasting
- e.g., carcinoids
Secretory diarrhea
75
endoc tumor in panc -> tumor increases sec of vasoactive intestinal polypeptide -> stim guanylate cyclase -> stim cGMP -> open Cl gate -> diarrhea
VIPoma or Vasoactive Intestinal Polypeptide tumor
aka "Pancreatic cholera"
76
- pseudodiarrhea
- d/t rapid transit of intestinal content
- e.g., hyperthyroidism, IBS
Dysmotility
77
- self-induced diarrhea, usual in women
- watery diarrhea w/ hypokalemia, weakness, and edema
- e.g, laxative abuse
Factitious diarrhea
78
- Immune med chronic intestinal cond
- Chronic recurrent inflam
- 2 types:
IBD
Ulcerative colitis
Crohn's dse
79
smoking may prevent what type of IBD?
UC
80
appendectomy may prevent what type of IBD?
CD
81
- CD4+ T cell activation -> sec inflam cytokines
- macrophage, B cells, inflam leukocytes, mononuclear cells are recruited
- proinflam > anriinflam
- normal flora is perceived as pathogen
IBD
82
- (+) immune response vs I2, Ompc and Flagellin
- improved with fecal diversion
- may benefit from metronidazole, ciprofloxacin
CD
83
- symmetrical lesions
- continuous distribution
- involves mucosa and submucosa
- rectal involvement
- backwash ileitis (mild involvement of the ileum)
- toxic megacolon (dilated large intestines -> prone to perforation)
- compli: colorectal adenoCA
UC
84
- asymmetrical
- segmental distribution
(1. ileocolic, 2. small colonic, 3. isolated colonic distribution)
- skip lesions
- transmural involvement (more layers are involved) -> deeper inflam -> heal -> scarring -> stricture -> obstruction
- rectal sparing
- small bowel involvement
- recurrence after surgery
- see granulomas (non-caseating), fissure, fistula (can form communication with other GI organs since this condition involves transmural)
- intestines may become palpable in emancipated px
CD
85
diagnostic tools in IBD
1. Biochemical
- elev acute phase reactants
- dec albumin
- dec hemoglobin
- in WBC
2. Imaging
- can ident CD
- not helpful in UC
3. Serologic markers
- pANCA -> UC
- ASCA -> CD
86
treatment in IBD
1. 5-ASA
2. Glucocorticoids
3. Antibiotics
4. Azathioprine/ 6 mercaptopurine
5. Methotrexate
6. Cyclosporine
7. Tacrolimus
8. Anti-TNF
87
- mainstay for mild-mod UC
- regulates NFKB (inflam med)
- induction and maintenance in both UC CD
- sulfasalazine, mesalamine, olsalazine
5-ASA
88
- induction
- for mod-severe UC CD
prednisone = 40-60 mg/d
budesonide = more localized, better
- prob: adrenal insuf, electrolyte imbal
Glucocorticoids
89
- for CD, no role in UC
- prevent recurrence
- metronidazole, cirpofloxacin
Antibiotics
90
- inhib immune response
- maintenance in both UC CD
Azathioprine/ 6 mercaptopurine
91
- anti-inflam
- dec Il1
induction and maintenance in CD
- also used in rheumatoid a
Methotraxate
92
- inhib cellular and humoral immune system
- block prod of Il2
- inhib B cell fxn
- for those refractry to iv steroids
- for induction
- no effect in maintenance if w/co azathioprine
Cyclosporine
93
- macrolide abx
- for refractory IBD and those w/ extensive small bowel involvement
Tacrolimus
94
- block TNF
- lyses TNF producing macrophage and T cells
- for induction and maintenance
anti tnf
infliximab, adalimumab, certolizumab, golimumab (antiTNF)
thalidomide (inhib tnf)
95
RF of colorectal CA
Diet
Insulin resistance
Dietary fiber
Hereditary factors and syndromes
IBD
Male
Obesity
Smoking
Physical activity
Polyps
96
insulin resistance as RF of colorectal CA
T2DM -> insulin resistance -> inc IGF -> stim prolif of intestinal cells
97
mech on how dietary fiber dec incidence of colon neoplasia
a. dilute/bind carcinogens and toxins
b. enhance elim
c. dec conc of fecal 20 bile acids and mutagens
d. dec bacterial metabolic enz-b glucoronidase
e. fermented by fecal flora to SCFA -> dec colonic pH -> less favorable for colon formation
98
Hereditary factors and syndromes
- 25% of px have (+) fam hx
- hereditary (autosomal dominant) GI Polyposis Syndromes (100k polyps)
- if px has syndrome = px has lot of polyps
Familial Adenomatous Polyposis
Gardner's syndrome
Turcot's syndrome
Non-polyposis coli syndrome
Peutz-Jegher's syndrome
Juvenile polyposis
99
histologic type w/ higher risk of malignant potential
most dev sympt at adolescence
then dev colon CA at 35
may die untreated at 40
Adenoma
100
IBD and colon CA
longer yr w/ IBD = higher risk of CA
px w/ pancolitis = higher risk
101
non-malignant polyp
Hamartomatous (Juvenile)
Hyperplastic Mucosal Proliferation Polyp
102
potentially malignant polyp
adenomatous polyp
103
histologic type w/ higher risk
villous 3x higher than tubular
104
polyp size
<1.0 cm : negligible(<2%)
1.5-2.5 cm : intermediate(2-10%)
>2.5 cm : substantial(>10%)
105
polyp gross w/ higher risk
sessile > pedunculated
106
AdenoCA sequence
normal colon -> daily mutagen or carcinogens -> chromosomal abnorm -> build up -> hyperprolif of colonic ell -> adenoma -> dysplasia -> adenoCA
107
majority of colon CA arise in ________
left side (60%)
descending colon, rectum
108
s/s of colon CA in the cecum and ascending colon
anemia
palpitation
weakness
possible occult blood
109
s/s of colon CA in the transverse and descending colon
obstruction (distention, ab pain) "apple core deformity"
perforation
110
s/s of colon CA in the recto sigmoid
tenesmus (painful straining)
narrowing stool caliber
hematochezia
111
mets of colon CA
regional LN
liver
lungs or supraclavicular LN via paravetebral veins
112
how many # of positive tumor cells = marker of microscopic spread
> 5
113
rectal bleed
red -> loc: small bowel, colon
black -> loc: upper GI
114
hard large stool followed by dripping of blood _______
stool is watery and bloody ______
anorectal area
lesion might be higher
115
ab pain
pain in the lower ab are often relieved by passage of stool or flatus
pain deep in the pelvis
pain in perineum
rectal pain
anal canal pain
116
herniations or sac-like protrusions of mucosa
incidental finding during colonoscopy
males at younger age
50% of affected px > or = 60 yrs
non-existent in the rectum bec of smooth m
diverticula of colon
117
most common loc of colon diverticula
left side -> sigmoid colon
in the taenia (weak part)
118
pathophy of colonic diverticula
colonic circ is supplied by nutrient artery -> nutrient artery penetrates muscularis -> becomes a weak point -> colonic pressure inc -> force the mucosa to herniate out -> diverticula
119
- mechanical retention of food residue and bacteria in the diverticulum
- left (3x) > right
- obstipation, tender on LLQ, fever
diverticulitis
120
colonoscopy in diverticulitis is not advised
pushing the scope inside -> may ppt perforation
121
- recurrent LLQ colicky pain w/o signs of diverticulitis
- relieved by defecation or passage of flatus
- alternate constip diarrhea
painful diverticular disease w/o signs of diverticulitis
122
- most common cause of painless bleed in px > 60 yo
- 20% of px w/ diverticula
- common in right colon
bleeding diverticulitis
123
- diagnostic and therapeutic for bleeding diverticula
- plug vessel to stop bleeding
angiographic treatment
embolization
124
- ab pain or discomfort w/ disturbed defecation
- absence of structural abnorm
- usual loc: lower GIT
- female, onset of sympt <45 yo, whites, blacks, nonhispanic whites>hispanic whites
IBS
125
- dx for IBS
- recurrent ab pain, at least 1 day/week
Rome IV criteria (2016)
126
IBS commonly presenting Type 1 and 2 bristol stool
IBS commonly presenting Type 6 and 7 bristol stool
IBS commonly presenting Type 1 and 6 bristol stool
IBS-C
IBS-D
IBS-M
127
pathophysio of IBS
- altered colonic and small intestine motility
for IBS-D (VS IBS-C)
- inc high amplitude propagated contractions (HAPC's)
- enhanced gastro-colic response
- rectal hypersensitivity
- Li and Si transit acceleration
128
- rectal distension causes more pain
- 60% of IBS px
- abnormal sensitization within dorsal horn of spinal cord or higher CNS
visceral hypersensitivity
129
fermentable oligo, di, monosac, and polyols
fodmap
*if px is dx w/ IBS = avoid high fodmap diet
130
- slow or non-digested substances osmotically active
- fermented in the colon - abdominal bloatedness
high fodmap
131
drug/s for IBS-D
anti-diarrhea
TCA e.g., desipramine
alonsetron-5-ht3 antagonist
132
drug/s for IBS-C
SSRI e.g., paroxetine
serotonin type 4 receptor antagonist e.g., tegaserod
