GI Viral diarrhea

Question 1

Whats the most common cause of diarrhea in little kids

Answer 1

viral illness: rotovirus pretty common norovirus more in adults

Question 2

What is the best tx with a kid that has diarrhea and is vomiting from viral illness?

Answer 2

oral rehydration!!! – Intestinal glucose absorption via sodium-glucose cotransport remains intact. – Intestine able to absorb water if glucose and salt are also present.

Question 3

Why is it important to have both Na and glucose in solutions for hydration?

Answer 3

the Na/GLU co transporter (SGLT-1) is non-ATP co transporter that requires both to be present and water will follow

Question 4

4 days of diarrhea, tired and weak with abdominal pain and now bloody stool. She’s orthostatic, with hyperactive bowel sounds and no peritoneal signs, Ddx?

Answer 4

Bacterial, infectious (inflammatory colitis) or non-infectious like Crohns or UC

Question 5

Do we treat bloody diarrhea with antibiotics or anti-diarrheals?

Answer 5

nope

Question 6

Most common cause of GI illness in children and how do we tx it?

Answer 6

viral hydration

Question 7

Causes of bloody diarrhrea

Answer 7

infectious: inflammatory mediated like shigella, E coli or campylobacter non-infectious: UC or crohns

Question 8

Pt with blood diarrhea has confirmed E.coli 0157:H7 and tx w/ cipro

now she is jaundiced, sceral icterus, difficulty breathing, rash, bilateral edema and anemic. What happened?

Answer 8

HUS

Question 9

– Travellers’ diarrhea and post infectious IBS

Answer 9

Enterotoxigenic E. coli

Question 10

– Guillain Barre Syndrome

– Crohn’s Mimic
– Pseudoappendicitis

Answer 10

Campylobacter

Question 11

– pet turtles

– Osteomyelitis in sickle cell/asplenic patients

Answer 11

Salmonella

Question 12

– Day care/institutions
– HUS, but less common (primarily S. dysenteriae)

– Seizures
– Reactive arthrit

Answer 12

Shigella

Question 13

– Shellfish contamination

Answer 13

vibrio cholerae

Question 14

– Most common cause world wide

– Cruise ships

Answer 14

Norovirus

Question 15

– Most common pediatric cause of GI illness

Answer 15

Rotavirus

Question 16

Pt is Acute, non-toxic appearing, non-bloody diarrhea, do we test?

Answer 16

– No testing is needed

Question 17

Key for stool cultures

• Bacterial pathogens generally are excreted :
• Negative culture usually not a :
• Repeat specimens are :

Answer 17

continuously.

false negative

rarely required

Question 18

When is it important to order a stool sample?

Answer 18

Severely ill

Outbreaks

Require hospitalization

Immunocompromised patients, e.g. HIV

Patients with co-morbidities (e.g. IBD)

Some employees, such as food handlers or daycare providers, may require negative stool cultures to return to work

Question 19

WHen and how do we provide emperic tx for travelers diarrhrea?

Answer 19

Moderate to severe travelers’ diarrhea

– > four stools daily, fever, blood, pus, or mucus in the stool.

Prompt treatment with fluoroquinolone or TMP-SMZ

– can reduce the duration from 3-5 to 1-2 days.

Question 20

When can we proved empiric antibiotics to pts with GI illness?

Answer 20

Greater than eight stools per day, volume depletion, symptoms >one week, hospitalized patients, and immunocompromised hosts

Fluoroquinolone for three to five days

Azithromycin and erythromycin are alternative agents particularly if fluoroquinolone resistance is suspected.

Question 21

When is it okay to use anti-motility agents for diarrhea

Answer 21

Only if fever is absent and stools not bloody – Bacterial translocation
– C. diffToxic megacolon

• These drugs may facilitate the development of the (HUS) in EHEC.

Question 22

• Neither the small intestine nor the colon can maintain an osmotic gradient
• Unabsorbed ions that remain in the lumen

– Retain water

– Maintain an intraluminal osmolality = 290 mOsm/kg (same as serum)

Answer 22

Osmotic diarrhea

Question 23

Causes of osmotic diarrhea

Answer 23

Ingestion of poorly absorbed ions or sugars or sugar alcohols

– Mannitol, sorbitol
– Magnesium, sulfate, and phosphate.

Monosaccharides—but not disaccharides—can be absorbed intact across the apical membrane of the intestine.

– Disaccharidase (lactase) deficiency will prevent absorption.

– “lactose intolerance”

Question 24

• Disappears with fasting Or cessation of the offending substance.
• Electrolyte absorption is not impaired in osmotic diarrhea
• Electrolyte concentrations in stool water are usually quite low

Answer 24

Secreatory Diarrhea

Question 25

Causes of Secreatory diarrhea

Answer 25

– Either net secretion of anions (chloride or bicarbonate) – Or inhibition of net sodium absorption.

The most common cause is infection.

Question 26

How do Enterotoxins cause secreatory diarrhrea?

Answer 26

– Interact with receptors and modulate intestinal transport

– Block specific absorptive pathways, in addition to stimulating secretion.

– Inhibit Na+-H+ exchange in both the small intestine and colon

Question 27

Osmotic Gap =

what is a normal gap?

Answer 27

Serum Osm – Est stool Osm

– Therefore, (2 × ([Na+] + [K+])) ~ 290 mmol/L.

*In secretory diarrhea, almost all of the osmotic activity of stool is accounted for by electrolytes

Question 28

What has a small osmotic gap, <50?

large osmotic gap like >100mOSm?

Answer 28

small seen in secreateory

large seen in osmotic

Question 29

Osmotic diarrhea

– Electrolytes only a small part of the osmotic activity

– Unmeasured osmoles account for most of the osmotic activity

– The calculated osmotic gap will be _____

– Osmotic gap is present at:

Answer 29

high.

(>100 mOsm/kg),

Question 30

Pt is found to have lactose intolerance, osmotic diarrhea and is anemic. she has history of osteopenia. What else is she at risk for?

Answer 30

Celiacs disease

Question 31

Diarrhea, bloating, ab pain and weith loss

Answer 31

celiacs

Question 32

What is the genetic susceptibility repsonsible for celiacs?

Answer 32

DQ2 or DQ8

Question 33

What tests + in pts with celiac sprue

Answer 33

IgA EMA or tTG positive: this is seen in pt with active Celiacs sprue and intestinal mucosal abnormality

Question 34

Shit associated with atypical sprue

Answer 34

Iron deficiency, osteoporosis, Dermatitis Herpetiformis, IBS, DM type I, elevated LFTs

Question 35

Prevelance of Celiacs

Answer 35

~1 in 100 in Northern European Descent

Prevalence of CD in at risk population – First-degree relatives: 1 in 10

– Second-degree relatives: 1 in 39 – Monozygotic twin 70-80%
– HLA identical sibs – 40 %

Screening in 1st degree relatives

Leads to diagnosis of asymptomatic CD

Question 36

Key for non-GI presenting Celiacs

Answer 36

Unexplained Fe deficiency anemia,

Folic acid or Vit B12 deficiency

reduced serum albumin

unexplained elevated LFTs

Question 37

autoimmune disorders associated with celiacs

Answer 37

– Type 1 diabetes mellitus (2% to 15%)

– Thyroid dysfunction (2% to 7%)

– Addison disease
– Primary Biliary Cirrhosis
– Sjogren’s Disease

– Autoimmune hepatitis (3% to 6%)

Question 38

Other shit associted with celiac

Answer 38

Down syndrome and Turner syndrome (6-14%)

• Selective IgA deficiency
– 2-5% of all patients with CD have IgA deficiency – 9% of all IgA-deficient patients have CD

Question 39

Pruitic papulovesicles on the extensor surface of extremeties and trunk often associated with celiacs (85% time) and ITCHY

Answer 39

Dermatitis Herpetiformis

Question 40

Most ocmmon non-GI presentaiton of CD

Answer 40

Osteopenia

– ~70% of patients with untreated CD

– ~30% Silent CD
Osteoporosis > 25% all CD patients
All newly diagnosed CD should have a Bone Density

Question 41

What malignancy are pts with celiac at increased risk for?

Answer 41

Enteropathy Associated T-cell Lymphoma

– High-grade T-cell NHL

– 5-year survival rate ~10%

– Occurs ~20 x more frequently in patients with CD

– Still very rare 9 of 381 in one study

Question 42

Serology used to diagnose Celiacs

Answer 42

– IgA Endomysial antibody (EMA)
– IgA Tissue Transglutaminase (tTG) (Best One)

– IgA and IgG Deamidated Gliadin Antibodies

Question 43

When do you get a small intestine biopsy for celiacs?

what do you see?

Answer 43

“Scalloping” or “Notching” of the small bowel folds.

• Following positive serology.

*Multiple biopsies should be obtained
– Total of six to eight biopsies probably optimal.

• Small intestinal villous atrophy, intraepithelial lymphocytosis, and crypt hyperplasia