Diarrhea DSA Flashcards
Clinical Dx of diarrhea
How long is acute diarrhea? Chronic?
3 or more loose/watery stools a day
OR
Decrease in consistency and increased frequency of BMs
<2 wks for acute
>4 wks for chronic
All inflammatory diarrheas (blood, pus, fever, etc.) require:
Stool bacterial cultures
Most common non-infectious cause of diarrhea
Meds - Abx, NSAIDs, anti-depressants, chemo, etc.
Sweeteners - Sorbitol
What features of diarrhea will warrant further workup?
Nocturnal diarrhea
Wt loss
Anemia
+ fecal occult blood test
Normal stool osmolality =
<50 mOsm/kg
Osmotic diarrhea
What happens to stool volume when fasting?
What is the stool osmotic gap?
Symptoms include:
Most common causes (4)
Stool volume decreases w/ fasting
Stool Osm gap: > 50-75 mOsm/kg
Abdominal distention, bloating, flatulence
Meds
Lactose intolerance
Laxative abuse
Malabsorptive syndromes
Secretory diarrhea
What happens to stool volume when fasting?
What is the stool osmotic gap?
Symptoms include:
Most common causes (4)
Stool volume does not improve w/ fasting
Normal Osm gap
High-volume watery diarrhea, dehydration (hyponatremia, NAGMA)
Endocrine tumors
Bile salt malabsorption
Factitious diarrhea (laxative abuse)
Villous adenoma
Which 2 parasites should be detected by fecal antigen?
Giardia
E. histolytica
Which 2 parasites should be detected by modified acid-fast staining?
Cryptosporidium
Cyclospora
Which patients should have an endoscopic exam and mucosal Bx?
Pts. w/ chronic persistent diarrhea
-IBD, microscopic colitis, clonic neoplasia, etc.
What signs/findings are consistent with pancreatic insufficiency vs. chronic pancreatitis?
Pancreatic insufficiency: fecal elastase < 100 mcg/g
Chronic pancreatitis: calcification on abdominal XR
How is small bowel bacterial overgrowth diagnosed? (2)
Non-invasive breath test (glucose or lactulose)
dConfirmed by obtaining an aspirate of SI contents for aerobic/anaerobic cultures
What does a H+ breath test help diagnose?
Lactase deficiency
Reported abnormalities in IBS (3)
Altered colonic motility at rest and response to stress, drugs, CCK
Altered SI motility
Enhanced visceral sensation - lower pain threshold
Patients with what unique symptomology may present with IBS?
Psychological disturbances
3 types of clinical presentation of IBS
- Spastic colon: chronic abdominal pain and constipation
- Alternating constipation and diarrhea
- Chronic, painless diarrhea
Pencil thin stools are common in:
IBS
At what point should IBS be in the differential?
In patients with diarrhea, bloating and flatulence, what should be excluded?
At least 3 mo. IBS usually diagnosed at 6 mo.
Lactose intolerance
What is used to diagnose IBS?
ROME IV clinical diagnostic criteria
What diet is used to treat/manage IBS?
Low FODMAPS diet
Fermentable oligosaccharides Oligosaccharides Disaccharides Monosaccharides Polyols
3 protists associated with chronic diarrhea
Giardia
E. histolytica
Cyclospora
What intestinal nematode is associated with chronic diarrhea?
Strongyloides
What bacteria is associated with chronic diarrhea?
C Diff
Diagnostics for C Diff (3)
Stool assay (toxins A and B) WBC > 15K Pseudomembranous colitis on sigmoidoscopy w/ volcano eruptions (not needed in most pts.)
Diarrheal type in C Diff
Mild to moderate geenish, foul-smelling watery diarrhea 5-15x a day
2 major complications with a C Diff infection
Toxic megacolon and hemodynamic instability
Microscopic colitis include which 2 variants?
Which patients are at the greatest risk?
What med is most often implicated?
Tx?
Lymphocytic and collagenous colitis
F>M; >50 y/o; idiopathic
NSAIDs
Tx anti-diarrheal w/ loperamide and stop offending agent
Symptoms of malabsorption syndromes (4)
Weight loss
Osmotic diarrhea
Steatorrhea
Nutritional deficiency
What damage occurs in Celiac disease?
What alleles are associated w/ Celiac?
Abs involved:
Diffuse damage to the proximal SI mucosa w/ malabsorption
HLA-DQ2 and HLA-DQ8
tTG abtibodies
3 atypical symptoms of Celiac disease
Dermatitis herpetiformis
Iron deficiency anemia
Osteoporosis
Major histological change in Celiacs
Complete loss of intestinal villi
What test is done to screen for osteoporosis in patients with sprues?
DEXA
Where are bile salts reabsorbed?
What causes destruction or loss of bile salts?
Steatorrhea? Weight loss?
Absorption of what is impaired?
What kind of diarrhea?
Terminal ileum
Bacterial overgrowth, acid hypersecretion, meds that bind bile salts
Mild steatorrhea, with minimal wt loss
Impaired absorption of fat-soluble vitamins (ADEK)
Watery diarrhea
Symptoms of Whipple disease
What is used to diagnose?
If untreated, it is…
Wt. loss, malabsorption, chronic diarrhea
Endoscopy w/ duodenal Bx with PAS stain (+ for Mo w/ characteristic bacillus)
Fatal
Pseudo-diarrhea =
Accompanies which pathologies?
Frequent passage of small volumes of stool
IBS and prostitis
Fecal incontinence =
What causes it?
Involuntary discharge of rectal contents
NM disorders pr structural problems
Overflow diarrhea =
Where is it seen?
What is readily found by rectal exam?
Severe constipation, only contents that get by is liquid
Elderly/nursing homes
Fecal impaction
What is melanosis coli? What causes it?
A benign hyperpigmentation of the colon caused by chronic laxative use
What is paradoxical diarrhea?
Diarrhea from stool leaking around impacted feces - “overflow incontinence”
In what case should you not do a DRE?
If pt. has leukopenia
What kind of diarrhea accompanies bile salt malabsorption?
Osmotic diarrhea
