DSA Diarrhea Flashcards
Pt. presents with changes in bowel habits after going on hiking trip. She reports packing her own food, but they did drink the stream water. Her VS are normal, but she reports a watery diarrhea, abdominal cramps, and bloating. Based on her history, and description, what casued this infection and what type of stool does she have?
Giardia lamblia
Type 7 on Bristol Stool Chart
When assessing a pt with diarrhea, what signs should you look for?
signs for malnutrition, IBD, dehydration
How do we clinically define diarrhea?
3 or more loose stools per day
or
decrease in consistency and increase in frequency of BM of pt
What do you see in acute diarrhea if non inflammatory? inflammatory?
acute diarrhea - lasts less than 2 weeks
a. noninflammatory: watery, mild, self-limited, viral or non invasive bacterial infection, only evaulate if severe for 7+ days
b. inflammatory: bloody, pus, fever, need to look for E. coli O157:H7, invasive or toxin producing bacterial infection
What is the most likely cause of diarrhea if greater then 14 days, but less than 4 weeks?
medications
commonly: NSAIDs, ABs, antidepressants, chemotherapeutic, antacids, laxatives
How do we treat antibiotic associated diarrhea?
discontinue ABs - will resolve spontaneously
*diarrhea occurs during the period of AB exposure
When is it considered chronic diarrhea?
> 4 weeks
What qualifies osmotic diarrhea?
osmotic gap of 50-75 (normal is <50)
diarrhea decreases with fasting
sx: diarrhea, bloating, flatulence, abd distention
What are the most common causes of osmotic diarrhea?
Medications
Disaccharidase def/carb malabsorption
Laxative abuse
Malabsorption syndromes
What are clues it is secretory diarrhea?
not improved with fasting
normal osmotic gap
increased intestinal secretion or decreased absorption
high volume, watery diarrhea
What are causes of secretory diarrhea?
Endocrine tumor
Bile salt malabsorption
Factitious diarrhea
Villous adenoma
What should a stool sample be tested for?
secretory vs. osmotic diarrhea - check electrolyes
malabsorption - Sudan stain
inflammatory - ex. fecal occult blood
infections - ex. fecal Ag for giardia and e. histolytica
What invasive test is needed in most cases of chronic diarrhea?
colonoscopy with mucosal biopsy
to rule out/in: IBD, microscopic colitis, colinic neoplasia
When would you do an upper endoscopy?
- a small intestinal malabsorptive disorder is suspected (celiac disease, Whipple disease)
- It may also be done in patients with advanced AIDS to document
- Cryptosporidium, Microsporida, and M avium- intracellulare infection
When do we see fecal elastase less than 100mcg/g? calcification on a plain abd radiograph?
a. pancreatic insufficiency
b. chronic pancreatitis
How can we test for carbohydrate malabsorption?
includes lactase deficiency
elimination trial 2-3 wks or hydrogen breath test
When you see these, think….?
a. vasoactive intestinal peptide (VIP)
b. calcitonin
c. gastrin
d. urinary 5-hydroxyindoleacetic acid (5-HIAA)
a. VIPoma
b. medullary thyroid carcinoma
c. zollinger-ellison syndrome
d. carcinoid
The presence of nocturnal diarrhea, weight loss, anemia, or positive results on fecal occult blood test (FOBT) are inconsistent with _____.
medications, IBS, lactase deficiency
What are the three types of clinical presentation of IBS?
- spastic colon (chronic abdominal pain and constipation)
- alternating constipation and diarrhea
- chronic, painless diarrhea
If you are suspecting your pt has IBS, and you hear an alarm sx, what should you do?
think of a new diagnosis
Pt. comes is dx with IBS, what is most likely true of this pt:
onset was before age 30
female (2x more then males)
abd pain and irregular bowel habits
How do we diagnose IBS?
Dietary restriction of what can improve IBS?
FODMAPS- fermentable oligosaccharides, disaccharides, monosaccharides, and polyols)
includes: fructose, lactose, fructans, wheat-based products, sorbitol, and raffinose
What are lactase def pts at risk of?
osteoporosis - calcium supplementation is recommended
What pathogens are most commonly associated with chronic diarrhea?
What is the most common cause of ab associated colitits?
C. difficile
clindamycin, cephalosporins, ampicillin, amoxicillin, fluoroquinolones
Why might a pt with GERD be at a higher risk for c. diff infection?
PPIs
What is “volcano” exudate a buzzword for?
exudate of neutrophils and fibrin seen in pseudomembranous colitis due to c. diff infection
What type of diarrhea occurs with ab associated colitis?
mild to moderate greenish, foul smelling water diarrhea 5-15 times per day
What is lymphocytic colitis and collagenous colitis?
What are the key features of a malabsorption syndrome?
weight loss*
osmotic diarrhea
steatorrhea
nutritional deficiency
*if not present, probably wrong dx
What serious signs might be associated with malabsorption
neurological –> vit B12 or vit E
hyperkeratosis –> vit A
easy bruising –> vit K
osteomalacia –> vit D
pallor –> anemia
What is seen on hx/PE of celiac patients?
What would the levels of antibodies be in celiac disease after 3-12 months of dietary gluten withdrawal?
undetectable
IgA tTG antibody
IgA anti-endomysial antibody
IgG antibody to deamidated gliadin peptides (anti-DGP)
What finding on biospy would exclude celiac disease?
normal biospy
should see blunting or complete loss of villi
What screening is recommended for all celiac pts?
dual-energy x-ray densitometry - screens for osteoporosis
Which will more likely show nutrient/vit def:
pancreatic insufficiency or bile salt malabsorption
bile salt malabsorption - impaired absorption of fat-soluble vitamins (A, D, E, K) is common
Pancreatic insufficiency: micellar function and intestinal absorption are normal so signs of nutrient or vitamin deficiencies are rar. e
What three conditions need to be clinically differentiated from chronic diarrhea?
If a pt has a fecal impaction, what is the only legit reason to not do a DRE?
pt has leukopenia
