Diarrhea & Constipation

Question 1

Rome IV criteria for IBS

Answer 1

abd pain at least one day/week for the past 3 months w/ 2 of the following:

• related to defecation
• a/w change in bowel frequency
• a/w change in stool form

Question 2

in pts suspects of having IBS-D, what must you evaluate

Answer 2

CBC, inflame markers, TTG IgA, total IgA

Question 3

what are red flags when eval for possible IBS

Answer 3

• onset age >50
• IDA, lab abnormalities like elevated inflammatory markers
• rectal bleeding
• nocturnal diarrhea
• unexplained wt loss
• fam h/o IBD or CRC

Question 4

True or False. if both HLA DQ2 and HLA DQ8 are negative, that excludes celiac disease

Answer 4

True

Question 5

what is the first line screening test for celiac in pts w/ IgA deficiency?

Answer 5

deaminated gliadin peptide (DGP) IgG

Question 6

what condition mimics celiac on histology and symptoms?

Answer 6

olmesartan-induced enteropathy

same histology (intraepithelial lymphocytes and villous blunting) but pt will have normal celiac serologies and will not respond to gluten-free diet.

you can also get intraepithelial lymphocytes and villous blunting w/ tropical sprue (but you’ll also get microcytic anemia and low albumin and travel history)

Question 7

True or False. IgA deficiency is more common among pts w/ celiac disease as compared to the general population

Answer 7

True

for pts w/ IgA deficiency, the screening test for celiac is DGP IgG (not IgA)

Question 8

dx of tropical sprue

tx of tropical sprue

Answer 8

dx - intraepithelial lymphocytes and villous blunting
negative celiac serologies. macrocytic anemia. low albumin.

tx - tetracycline and folate

Question 9

Whipple’s disease

• presentation
• eval
• tx

Answer 9

Whipple’s disease

middle-aged white male
wt loss, diarrhea, abd pain
intermittent, migratory arthralgias
neuro sx (confusion, depression, personality changes, nystagmus, rhythmic contractions of muscles in the face)

Diagnosis
EGD w/ biopsies of duodenum (histology shows PAS+ macrophages in lamina proper)
confirm w/ immunohistochemistry or PCR

tx
prolonged (12+ months) of abx. usually w/ IV induction (PCN, ceftriaxone) followed by PO Bactrim

Question 10

how do you calculate stool osm gap? what is a normal range?

Answer 10

stool osm gap = 290 - 2(Na + K)

normal range is 50-100
osmotic diarrhea = osm gap > 100
secretory diarrhea = osm gap <50