Infectious Diarrhea Flashcards
Differentiate diarrhea from…
Pseudodiarrhea - Rectal urgency, infection related
Fecal incontinence - Sudden, surprise discharge, NM related
Overflow incontenence - So packed up, liquid distends and flows around and leaks out
Amount of fluid entering Small Intestine?
Entering Large Intestine?
Exiting in normal stool?
9 L
2 L
0.1 L
Diarrhea reflects increased water in stool from…
- Increased Intestinal Secretion of Water
2. Decreased intestinal reabsorption of water
Duration of Acute, Persistent, and Chronic Diarrhea
Acute - Less than 14 days
Persistent - 14-30 days
Chronic - More than 30 days
Three primary types of Chronic Diarrhea
Watery
Fatty
Inflammatory
Common causes of Watery Chronic Diarrhea
Secretory (Colitis, Laxatives)
Osmotic (Laxatives)
Functional (Irritable Bowel)
Way of differentiating between Secretory and other causes of chronic watery diarrhea
Secretory will persist despite fasting
Causes of chronic fatty diarrhea
Malabsorption (Giardiasis, Celiac)
Maldigestion (Pancreatitis, Cystic Fibrosis)
What should you look for as an identified of chronic fatty diarrhea from maldigestion
Meat fibers in the stool
Causes of inflammatory chronic diarrhea (pus/blood in stool)
IBD (Ulcerative Colitis, Crohn’s)
Invasive (C Diff)
Neoplasia (Colon carcinoma)
Causes of Acute Diarrhea
- Usually viral
- Bacteria (esp. w/ blood, pus, fever, abdom. pain)
- Rarely Protozoa
Value of Stool Cultures?
Rarely valuable, consider in cases in which other results aren’t seen
Enteric pathogens that have preformed toxins
Site of Action?
Small Bowel – C. perfringens, S. Aureus, B. cereus
Colon – None
Enteric pathogens with enterotoxin?
Site of Action?
Small – Vibrio Cholerae
Colon – None
Enteric pathogens that are enteroadherent?
Site of Action?
Small – Giardia lamblia
Colon – None
Enteric pathogens that act with a cytotoxin?
Site of Action?
Small – None
Colon – E. Coli 0157:H7
Enteric Pathogens that cause dysentery?
Small – Salmonella, E. Coli
Colon - Campylobacter, Shigella, Entamoeba histolytica
Viruses that affect the Small Bowel
Rotovirus
Norovirus
Viruses that affect the colon
CMV
Adeno
Herpes
Common Associations – Vomiting. Cream Pie/Potato Salad at a picnic
S. aureus
Common Associations – Vomiting. Leftover Fried Rice.
B. cereus
Common Associations – Vomiting. Cruise Ships.
Norwalk-like viruses
Common Associations – Inflammatory Diarrhea. Hamburgers at a picnic.
Salmonella
Common Associations – Inflammatory Diarrhea. Hamburgers, Spinach
E. Coli 0157:H7
Common Associations – Inflammatory Diarrhea. Sushi
V. parahemolyticus
Common Associations – Inflammatory Diarrhea. Raw oysters in a place they probably shouldn’t be serving them.
V. vulnificus
What happens if you eat C. perfringens toxin. (Think home canned foods)
Toxin mediated acute GI symptoms
Gastroenteritis
What happens if you eat C. perfringens bacteria.
Pig Bel (Necrotizing Enteritis) (Look for high fever, distended abdomen)
Effects of C. botulinum
Paralytic neurotoxin released in anaerobic environment
Weakness, diplopia, progresses to paralysis
Effects of C. tetani
Excitatory neurotoxin formed by bacteria present in wounds
Lockjaw
Effects of C difficile
Toxin mediated colitis from C dif overgrowth
Pseudomembranous Colitis
Virus associated with daycare exposure
Rotavirus
Virus associated with cruise ships
Norovirus
Virus associated with MSM, Shellfish, Food workers
Hep A
Protazoa associated with travel, surface water.
Giardia lamblia
Bacteria associated with Traveler’s Diarrhea (travels to the developing world)
ETEC
Bacteria associated with antibiotic use in the past 3-6 months.
C. difficile
Bacteria associated with Caesar salad, ice cream, ducklings, lizards
Salmonella
Seven components of a full diarrhea history
Onset Frequency Presence of mucous/blood Getting up at night? Associated symptoms Exposures (Travel, Camping, Other sick people, etc.) Recent AB use?
Describe a Bristol Stool Chart Type 1
Separate hard lumps, like nuts
Hard to pass
Describe a Bristol Stool Chart Type 2
Sausage shaped, but lumpy
Describe a Bristol Stool Chart Type 3
Like a sausage, but with cracks on the surface
Describe a Bristol Stool Chart Type 4
Like a sausage or snake
Smooth and soft
Describe a Bristol Stool Chart Type 5
Soft blobs with clear cut edges
Describe a Bristol Stool Chart Type 6
Fluffy pieces with ragged edges
Mushy
Describe a Bristol Stool Chart Type 7
Watery, No solid pieces
Signs of a surgical abdomen
Guarding, Rebound, increased pain/tenderness
Distended, No Bowel Sounds
Why should you be looking at the skin in a diarrhea physical exam
There are rashes associated with some pathogens.
Ex. Look for a on-blanching rash (Vasculitis)
Specifically mentioned piece of information gathered in a rectal exam.
Hemoccult
Other phrase for hemorrhoids
Sentinel Piles
What is an anal fissure? How does it happen?
Worry about it?
A tear in the anus
Typically associated with trauma (Anal sex, BM) and hematochezia
Usually not super pathological
What is hematochezia
passage of fresh blood through the anus
What is an anal fistula? How does it happen?
Worry about it?
Chronic abnormal communication between the epithelialised surface of the anal canal and the perianal skin associated with IBD.
Associated with much higher risk of severe anorectal disease.
When a patient comes in claiming to have hemorrhoids, what should you check to make sure it isnt
HPV/Anorectal Warts
Describe the evaluation steps for an acute diarrhea patient.
Initial Eval – Dehydration, inflammation
Symptomatic Therapy
If not severe, wait a week with symptomatic aids
If severe, test for fecal leukocytes, stool culture
Antibiotics if inflammatory, symptomatic if noninflammatory
What might be an indicator you need to check for Ova/parasites in stool?
Persistent Diarrhea Travel (Russia, Nepal) Exposure to infants in daycare centers MSM, AIDS Community Outbreak Bloody with few/no leukocytes
What do you do if you have persistent bloody diarrhea but your bacterial + cultures are getting you nowhere
Endoscopy (Look for tricky Inflammatory Bowel Disease)
Recipe for oral rehydration mix
half tsp salt
half tsp baking soda
4 tbs sugar
1 L water
Three commonly used symptomatic therapies for diarrhea
Loperamide (Immodium) – Anti-motility agent
Diphenoxylate (Lomotil) – Anti Motility agent
Bismuth subsalicylate (Pepto-bismol)
5 commonly used steps in treatment of acute diarrhea
Oral Rehydration Symptomatic Therapy Probiotics Dietary Alterations Empiric antibiotics
Two commonly used probiotics
Align, Culturelle
Commonly recommended dietary alterations for acute diarrhea patients
Avoid Dairy (temporary lactase loss) Low Residue Diet (white foods, cooked vegetables, low fat meats)
Most commonly used empiric antibiotics for diarrhea
Fluoroquinolone (Cipro, levofloxacin)
Metronidazole
Where should you look for stones in an abdominal x-ray
Ureter rides along in the psoas shadow
Two types of abdominal x ray
KUB (kidney, ureter, bladder)
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