Diarrhea, Malabsorption, Small Intestinal Neoplasia

Question 1

inflammatory diarrhea features

Answer 1

• small volume
• frank or occult blood
• rectal urgency
• abd pain
• NOCTURNAL DIARRHEA

Question 2

examples of inflammatory diarrhea

Answer 2

inflammatory bowel disease
ischemic colitis
radiation colitis
microscopic colitis

Question 3

microscopic colitis usually presents with bloody or non-blood diarrhea?

Answer 3

non-bloody diarrhea

Question 4

T/F

osmotic diarrhea resolves with eating

Answer 4

F

resolves w/o eating

Question 5

exp of osmotic diarrhea

Answer 5

• carb malabsorption (lactose intolerance)
• ingestion of poorly absorbed sugars (sorbitol, xylitol)
• laxatives w/ Mg

Question 6

secretory diarrhea

Answer 6

large volume watery diarrhea, minimal resolution w/ fasting

bile acid malabsorption
endocrine disorders
meds (abx, chemo, PPIs)
neoplasms (carcinoid, gastrinoma)

Question 7

dysmotility

Answer 7

intermittent, small volume, watery diarrhea

irritable bowel syndrome
postvagotomy

Question 8

causes of steatorrhea

Answer 8

• impaired fat solubilization (bile salt deficiency/inactivation)
• defective nutrient hydrolysis (exocrine pancreatic insufficiency)
• mucosal disease (celiac, chronic mesenteric ischemia, Chron’s)

Question 9

celiac disease

Answer 9

-immune mediated enteropathy triggered by gluten in genetically susceptible patients

• type IV HS
• Abs to tissue transglutaminase (TTG)
• T cell chronic inflamm in SI; proximal small intestine > distal

Question 10

predisposing genetics of celiac

Answer 10

HLA-DQ2

HLA-DQ8

Question 11

celiac epidemiology

Answer 11

• usu dx during childhood, but can be any age

- Northern Europe comm but everywhere

Question 12

Celiac pathogenesis

Answer 12

• gluten proteins resist degradation, lg peptides pass epithelium
• CD4+ T mediate disease
• TTG Abs

Question 13

celiac presentation

Answer 13

crampy abd pain
chronic diarrhea
Fe deficiency
osteoporosis
easy bruising
peripheral neuropathy 
seizures

Question 14

dermatitis herpetiformis

Answer 14

celiac

• IgA deposits, pruritis, blistering
• resolves w/ gluten free diet

Question 15

celiac assoc conditions

Answer 15

SI adenocarcinoma
SI intestinal adenocarcinoma
lymphocytic gastritis and colitis (microscopic colitis)

Question 16

tissue transglutaminase Abs

dx for

Answer 16

celiac

Question 17

celiac histo

Answer 17

increased intraepithelial lymphocytes

villous atrophy

crypt hyperplasia

Question 18

Celiac tx

Answer 18

gluten free diet

Fe, vitamin D/B12, Ca supp

Question 19

SI bacterial overgrowth syndrome

Answer 19

Intestinal stasis

Abnormal connections between proximal/distal bowel (fistulas)

Question 20

bacterial overgrowth

Answer 20

• reduced nutrient availability

- bile salt inactivation

Question 21

dx of SI bacterial overgrowth syndrome

Answer 21

• direct aspiration of jejunal contents

- H breath tests

Question 22

early peak in elevation of H2 concentration (in H breath test)

Answer 22

bacterial overgrowth syndrome

Question 23

inc bile salt losses

Answer 23

mucosal disease in terminal ileum (Chron’s)

surgical resection/bypass of ileum

overwhelmed absorptive capacity of ileum

Question 24

bile acid sequestrations

Answer 24

+ charged resin bunds to - bile salts and inc excretion

leads to liver inc bile acid synthesis which completes w/ CHL synthesis and ultimately lowers CHL levels

diarrhea tx

Question 25

most common cause of chronic pancreatitis

Answer 25

EtOH

Question 26

cystic fibrosis is a cause of ___ pancreatitis

Answer 26

chronic

Question 27

most sensitive/specific test for pancreatic insufficiency

Answer 27

fecal elastase (low in exocrine insufficiency)

Question 28

fat malabsorption tests

Answer 28

clinical hx | measure fat soluble vitamins

Question 29

atrophy of intestinal villi with inc intraepithelial lymphocytes

Answer 29

celiac

Question 30

late peak in H+ breath test

Answer 30

lactose intolerance

Question 31

fecal osmotic gap

Answer 31

osmotic diarrhea > 125

Question 32

osmotic diarrhea

Answer 32

lactose intolerance | lactose --> bacteria --> fermentation products --> water drawn in

Question 33

secretory diarrhea

Answer 33

abnormal ion transport in intestinal epithelial cells dec absorption of electrolytes or inc secretion of electrolytes major solutes in intestinal lumen account for most of luminal osmolality

Question 34

most common location of GI neuroendocrine tumors

Answer 34

ileum

Question 35

type 1 gastric NET

Answer 35

assoc w/ atrophic gastritis

Question 36

type 2 gastric NETs

Answer 36

assoc w/ multiple endocrine neoplasia syndrome (MEN-1)

Question 37

type 3 gastric NETs

Answer 37

sporadic | no underlying risk fx

Question 38

carcinoid syndrome

Answer 38

- uncommon in pts w/ carcinoid tumors - diarrhea, cutaneous flushing, bronchoconstriction, R sided HF flushing/diarrhea due to secretion of amines (serotonin) and peptides (bradykinin, tachykinins)

Question 39

carcinoid syndrome is often seen in metastatic disease to

Answer 39

liver

Question 40

carcinoid syndrome dx

Answer 40

labs: serotonin level, serum chromogranin A Imaging (CT, ocreotide scans) tx: surgical resection

Question 41

positive stains for carcinoid tumor

Answer 41

synaptophysin | chromogranin

Question 42

ocreotide

Answer 42

analog of somatostatin - somatostatin receptors found on carcinoid cells - inhibits secretion of serotonin, gastrin, vasoactive intestinal polypeptide, insulin, other hormones - improves diarrhea, flushing - also a splanchnic vasoconstrictor (used in GI bleeds)

Question 43

benign neoplasms of small bowel

Answer 43

adenomas puetz-jeghers hamartomas GIST

Question 44

malignant tumors of small bowel

Answer 44

``` adenocarcinoma ampullarf carcinoma primary intestinal lymphoma (MALT) carcinoid (neuroendocrine) tumor metastatic tumors ** most comm ```

Question 45

irritable bowel syndrome

Answer 45

functional GI disorder abd pain + altered bowel habits no biochemical or structural abnormalities

Question 46

IBS hx

Answer 46

older adult nocturnal wakening labs: anemia, inc WBC, inc ESR, CRP + fecal occult blood

Question 47

pathophys of IBS

Answer 47

- poorly understood - altered intestinal motility - heightened visceral sensitivity - visceral hyper responsiveness to luminal GI events

Question 48

IBS tx

Answer 48

- diet adjustments - antispasmodics (hyoscyamine and dicyclomine) - bulking agents - antidiarrheals - antidepressants - alosetron - behavioral therapy - probiotics - antibiotics

Question 49

rifaximin

Answer 49

- antimicrobial agent that interferes w/ bacterial protein synthesis - use: IBS-diarrhea