GI Flashcards
Crohn’s dx vs ulcerative colitis
Crohn’s disease tends to present
more frequently with abdominal pain and perianal disease, whereas ulcerative colitis is more often characterized by gastrointestinal bleeding. Cobblestoning mucosa
and aphthous or linear ulcers characterize the endoscopic appearance of Crohn’s disease. Ulcerative colitis presents with diffuse continuous involvement of the
mucosa often entire colon. Radiographic studies of patients with Crohn’s disease characteristically show fistulae, asymmetry, and ileal involvement. In contrast, radiographic studies of
patients with ulcerative colitis show continuous disease without fistulizing or ileal disease. Pathologically, Crohn’s disease features mucosal discontinuity, transmural
involvement, and granulomas, whereas ulcerative colitis does not. Crypt abscesses and granulomas are present only in Crohn’s disease
Screening algorithm for Hep C
Hepatitis C Antibody test (Anti-HCV) If positive, do confirmation with HCV RNA testing. If positive, the patient had a recent Hep C infection
When and how to test for H. Pylori success after treatment?
At least 1 month after Abx and 2 wks after stopping PPI
Urea breath test best
What is procalcitonin test helpful for?
Is an inflammatory process due to bacterial infection?
May be useful in guiding Abx use in sepsis and Respiratory Infections
what is the definition of chronic diarrhea
Change in consistency of stools for 4 weeks and is divided into watery, fatty and inflammatory
Persistent diarrhea 2-4 wks
Acute up to 2 wks
inflammatory diarrhea vs non inflammatory diarrhea
infection/ IBD - sometimes fever
secretory or osmotic
secretory vs osmotic diarrhea
secretory - increased active water secretion, decreased absorption - Most common cause is infection
osmotic - lumen has unreabsorbed nutrients which pull water in through osmosis - Most common cause is absorption issue like mag citrate, malabsorption dx
what describes most acute watery diarrhea?
Non-inflammatory, secretory.
Describe timing of food ingestion related diarrhea that suggests the pathogen cause
6 hours- pre existing toxin from staph a. or b. cereus
8-16 hrs- Clostridia perfringens
>16 enterotoxigenic E.coli
bloody, mucousy diarrhea suggests…
Inflammatory diarrhea and associated with abdominal pain, fever. Can be from pathogens SSYCE. Salmonella, Shigella, Yersinia, Campy, Enteroinvasive E. coli. or C. diff
Describe degrees of dehydration
Mild- 5% Moderate 5-10% Severe >10%
What is the cause of Hemolytic Uremic Syndrome
Most commonly (90%) seen in children after a bout of diarrhea. Multiple infectious diarrhea agents can cause it but think Shiga toxin from E. coli 0157. Associated with anemia, thrombocytopenia and potential renal failure. Often see purpura on legs. Atypical (10%) not diarrhea related
Think Triad: Hemolytic anemia (microangiopathic), Thrombocytopenia, AKI (acute kidney injury)
What is fecal lactoferrin
Fecal lactoferrin is sensitive and specific for detecting inflammation in chronic IBD. This noninvasive test may prove useful in screening for inflammation in patients presenting with abdominal pain and diarrhea- Helps separate out those who need more urgent work-up vs a functional diarrhea
What is the classic cause of functional diarrhea
Hypermotility, IBS
Describe food borne illness- preformed toxin vs infection
The two common causes of food poisoning are those caused by infectious pathogens (bacteria, viruses and parasites) and those caused preformed toxins. It is important to differentiate between the two.
Food poisoning due to preformed toxins presents within 6 hours and patient presents with upper gastrointestinal symptoms, predominantly vomiting, gastritis, etc. The commonest is Staph aureus, Bacillus cereus emetic toxin. On the other hand, bacterial food poisoning presents after 6 hours. The predominant symptom is diarrhea with or without vomiting.
Symptoms after 24 hours are due to pathogens that make toxin once they have been ingested. They mainly cause diarrhea that may be watery (Vibrio cholerae or E. coli) or bloody (Shiga toxin-producing E. coli).
Symptoms that occur after variable time are due to microbes that cause pathology by either damaging the epithelial cell surface or by actually invading across the intestinal epithelial cell barrier. They can produce a wide spectrum of clinical presentations from watery diarrhea (Cryptosporidium parvum, enteric viruses) to inflammatory diarrhea (Salmonella, Campylobacter, Shigella) or systemic disease (L. monocytogenes).
