Lecture 10: Small Bowel and Colon Disorders Flashcards
What is the Bristol Stool Chart and how does Type 1 differ from Type 7?
- Type 1 is on the constipated end of the spectrum w/ stool equal to hard lumps, like nuts (hard to pass)
- Type 7 is on the diarrhea end of the spectrum and is watery w/ no solid pieces (entirely liquid)
What is the major cause of death associated with diarrhea?
Dehydration
Diarrhea for >14 days is most commonly due to a (infectious/non-infectious) cause?
Likely non-infectious —> think meds!
If a workup is indicated for acute diarrhea which serum labs should you get?
- CBC
- Electrolytes
- BUN
- Cr
- Blood culture?
Most routine (bacterial) stool cultures include which 4 organisms?
- Salmonella
- Shigella
- E. coli (ask for shiga-like toxin detection for O157:H7 EHEC)
- Most detect campylobacter (although may need to be requested)
Food poisoning from which bacteria is commonly seen after ingestion of potato salad, mayonnaise or cream pastries?
S. aureus = Gram (+) cocci
Food poisoning by which bacteria is most commonly associated with ingestion of lunch meat and unpasteurized dairy?
Listeria monocytogenes** –> **Gram (+) rod
What virulence factor does S. aureus contain that leads to the sx’s of food poisoning?
Type of diarrhea?
- Preformed enterotoxins
- Watery diarrhea
Which bacteria is associated with food poisoning from fried rice?
Type of diarrhea and what is the main symptom?
- Bacillus cereus –> Gram (+) rod
- Watery diarrhea
- Vomiting is the main symptom!
Which gram-positive spore-forming rod is associated with food poisoning as a result of consuming inadequately cooked beef, ham, poultry, legumes, or gravy?
Type of diarrhea?
- Clostridium perfringens
- Watery diarrhea
Shigella spp. food poisoning is most commonly associated with what types of food?
Potato or egg salad, lettuce, raw vegetables
What type of diarrhea and symptoms are associated with Shigella spp. food poisoning?
Begins as watery —> intense colitis w/ fever and frequent small volume stools w/ blood and pus
Shigella spp. infection will have what finding in the stool of infected pt?
Fecal leukocytes (+)
What are post-infectious complications of Shigella spp.?
- Reactive arthritis
- HUS
Complications associated with Salmonella typhimurium?
- Reactive arthritis
- Endocarditis
- Septic arthritis
- Osteomyelitis (sickle-cell pts)
Vibrio parahemolyticus is associated with food poisoning from the consumption of what?
What kind of diarrhea?
- Seafood (i.e., shellfish, oysters, shrimp)
- Watery —> bloody diarrhea
Where is Vibrio vulnificus found?
Most often infects people via what 2 routes?
Common symptoms associated with each route?
- Warm, shallow, coastal salt water
- Eating raw shellfish (oysters) –> vomiting and diarrhea
- Open wounds in the water –> bullous skin lesions
Vibrio vulnificus infections are life threatening in which patients?
- Immunocompromised
- Especially cirrhosis and hemochromatosis pts
Aeromonas hydrophila is found in which enviornments?
Most often transmitted how?
- Fresh water or brackish water (slightly salty)
- Eating fish or shellfish
- Wounded in the water or open wounds in water
Which type of diarrhea can be produced by Aeromonas hydrophila? (2 types)
- Cholera-like: watery rice water stools
- Bloody mucoid stools
If someone sustains a wound while in fresh water and then has a rapidly progressive wound infection (i.e., necrotizing fasciitis), which bacteria should be susepcted?
Aeromonas hydrophila
What are positive serum and fecal findings associated with EHEC infection?
- Peripheral leukocytes (+) - CBC
- Fecal leukocytes or lactoferrin (+)
- Stool culture = shiga-like toxin
Antibiotic therapy for EHEC increases the risk for?
HUS
Infections by Yersinia enterocolitica poses a higher risk in which patients?
- Pts w/ derangement of iron metabolism
- Iron-overload syndromes, cirrhosis, hemochromatosis, aplastic anemia, and thalassemia
Infection by which bacteria can mimic appendicitis due to its localization to the terminal ileum?
Yersinia enterocolitica
Listeria monocytogenes can infect anybody, but has a predilection for whom?
- Pregnant women
- Extremes of age
- Immunosuppressed
- Those w/ Hemochromatosis
How is C. difficile diagnosed?
Stool culture - PCR for toxin (TcdA and TcdB)
Which 4 antibiotics are most commonly associated with infection with C. difficile?
1) Clindamycin
2) Ampicillin
3) Cephalosporins (3rd gens)
4) Fluoroquinolones
Best preventative measure for minimizing transmission and infection of C. difficile in a hospital setting?
Wash hands w/ soap and water + use of disposable gloves
How is Rotavirus detected?
Characteristic finding on electron microscopy?
- Detected by viral culture PCR
- “Wagon-wheel” appearance on electron microscopy
Who is most commonly affected by Adenovirus and what are the most common symptoms?
- Children
- Fever, chills, myalgias, sore throat
- Watery diarrhea
- Conjunctivits
- Pharyngitis
How is the Dx of Strongyloides stercoralis made?
- Rhabditiform larvae in stool
- Eosinophils in stool
Which organism is the 2nd most common cause of Esophageal Varices in Africa?
What other complications?
- Schistosoma mansoni
- Bloody stools, bladder cancer, and liver cysts
Which organism can form cysts in the liver or lungs, which characteristically looks like free-flowing “hydatid sand” on CT?
Echinococcus granulosus
Which 2 bacteria are most often responsible for inflammatory diarrhea w/ fecal leukocytes and fecal lactoferrin but not typically bloody stools?
- Listeria monocytogenes
- Clostridium difficile
Anti-motility agents may be used in patients in whom no fever and non-bloody stools exist, but are not to be used if infection is due to which 2 organisms?
- C. diff
- EHEC
Chronic use of what can lead to melanosis coli, a benign hyperpigmentation of the colon?
Laxitives
The presence of abdominal pain with chronic diarrhea (>4 wks duration) suggests which 2 disorders may be present?
1) IBS
2) IBD
Before embarking on an extensive evaluation for the cause of someones chronic diarrhea the most common causes should be considered which include what 3 things?
1) Medications
2) IBS
3) Lactose intolerance
Which signs/symptoms and findings are inconsistent with the most common causes of chronic diarrhea (i.e., red flags) and warrant further evaluation?
- Presence of nocturnal diarrhea
- Weight loss
- Anemia
- Positive FOBT
Evaluation of chronic diarrhea showing a fecal elastase <100 mcg/g may point to what underlying problem?
Pancreatic insufficiency
Neuroendocrine tumors may be localized via what imaging modality?
Somatostatin receptor scintigraphy
A patient with chronic, high-volume watery diarrhea (>1L/day) with normal osmotic gap that persists during fasting should raise suspicion of which disorder?
Neuroendocrine tumor