1. DIARRHEA
WHAT TO ORDER

2. Criteria for Conducting Stool Studies:
Perform a complete history which includes the following:
Travel history
Sexual practices
Antibiotics in the past 2 months or usage any other medications
Attendance of large group gatherings where others have become ill with same symptoms
Recent surgeries or procedures
Recent meals
Water source
Pets (high risk are snakes, turtles)
Onset and duration of illness

3. Criteria for Conducting Stool Studies:
Does the patient have the following:
Fever >101.3 F
Bloody stools
Symptoms of dehydration
Worsening diarrhea after 48 hours
Six or more stool samples in 24 hours
Advanced age (>70 years of age)
Compromised immune system
Age greater than 50 with severe abdominal pain

4. DIARRHEA
Definition:
To most patients, diarrhea means an increased frequency and/or decreased consistency of bowel movements.

5. Diarrhea
Diarrhea occurs because more fluid passes through the large intestine than can be absorbed.
Caused by:
Infections or illnesses
Excess production of fluids
Inability to absorb fluids
Certain substances in the colon, such as fats and bile acids
Interfere with water absorption
Rapid passage of material through the colon

6. Diarrhea Cont… Diarrhea can be classified as:
Acute, which lasts one or two weeks
Chronic, which continues for longer than 2 or 3 weeks.
The most common causes of acute diarrhea are:
Infections (viral or bacterial)
Food poisoning
Frequently overlooked:
Medications especially antibiotics, antacids, laxatives
various sugar free foods
sometimes contain poorly absorbable materials

7. Causes of Acute Diarrhea
Bacterial Infection
Indications for stool culture:
Bloody diarrhea
Fever
Tenesmus
Persistent or severe symptoms
Recent travel to a third world country
Known exposure to bacterial agent
Presence of fecal leukocytes
Stool Culture
Campylobacter, Salmonella, Shigella, E. coli 0157:H7
Coming soon: Shiga toxins

8. Causes of Acute Diarrhea
Shiga toxin
Produced by enterohemorrhagic E. coli strains
Most famous serotype is O157:H7
Others include O26, O103, O111, O145
Shiga toxin 1 (ST1) and Shiga toxin 2 (ST2)
Only one may be present, or both
CDC recommendation

9. Causes of Acute Diarrhea
Yersinia Culture
Not included in routine stool culture
Primarily affects young adults and immunocompromised individuals
Indicators for Yersinia culture
Exposure to contaminated pork, milk, water, tofu
Exposure to contaminated blood via blood transfusions
Sheds for 90 days after symptoms are resolved
Early detection key in prevention of transmission and outbreaks

10. Causes of Acute Diarrhea Cont…
Bacterial cont….
CDA Toxin (caused by Clostridium difficle)
10x more likely to affect >65 year olds than any other age group
Indicators
Extended hospital or nursing home stay post treatment with antibiotics accompanied with the following:
Watery diarrhea (>3 times a day for >3 days)
Fever
Severe abdominal cramps/pain
Presence of fecal blood

11. C. difficile toxin (CDA)
Most often diarrhea is caused by antibiotics or nosocomial infection
Rapid kits test for toxin A and toxin B
Do not order C. difficile culture
Not all strains of C. difficile produce toxin
Test of cure is NOT a negative toxin assay
Toxin is shed for period of time after diarrhea is resolved
Hard, non liquid stool will be rejected

12. Causes of Acute Diarrhea Cont…
Viral Infection
Rotavirus
Most common cause of viral diarrhea in infants and young children (up to 3 years of age)
May affect all ages, especially the elderly and the immunocompromised
Extremely contagious
Indications for performing test:
Fever >101 F
Vomiting
Watery stools lasting 5 to 7 days

13. Causes of Acute Diarrhea Cont…
Parasitic Infection
Giardia/Cryptosporidium Screen
Giardia and Cryptosporidium are the most common causes of diarrhea
Indicators
Exposure to contaminated water, food, or soil
Acute, watery diarrhea accompanied with
Excess gas
Stomach/abdominal pain
Nausea

14. Chronic Diarrhea
Chronic diarrhea is frequently due to many of the same things (infections, medications, etc.); symptoms just last longer.
Parasitic Infections
AIDS
colon cancer and other bowel tumors
endocrine or hormonal abnormalities (thyroid, diabetes mellitus, etc.)
food allergy
inflammatory bowel disease (Crohn's disease and ulcerative colitis)
lactose intolerance
malabsorption syndromes (celiac and Whipple's disease)
other (alcohol, microscopic colitis, radiation, surgery)

15. Chronic Diarrhea Cont…
Parasitic Infection
Ova and Parasite
3 samples over 10 day period recommended
Indicators for ordering
Suspected parasitic infection
Prolonged diarrhea with unknown origin
Diarrhea with few leukocytes present
Immunocompromised individuals
History of foreign travel or travel to mountainous areas of North America
Children in daycare
Not typically indicated for acute diarrhea

16. Causes of Chronic Diarrhea Cont…
Ova and Parasite Cont…
Test includes:
Fecal Concentration Exam,
Fecal Trichrome Stain:
Giardia/Cryptospiridium Antigen Assay
Does not include exam for:
Cyclospora, Isospora
Most common in our area is Giardia
History is extremely important

17. Complete Stool Exam At Salina Regional, Complete Stool Exam includes:
Stool Color & Consistency
Presence of gross blood
Occult blood
Stool pH
Giardia/Cryptosporidium antigen assays
Presence of charcot-leydon crystals, meat fibers, neutral fat, split fat, RBCs, & WBCs
Wet mount exam for parasites

18. Complete Stool Exam Cont…
Tests not included:
C. Diff Toxin (CDA) or Culture
Stool Culture
Yesinia Culture
O&P
Reducing substances

19. Occult Blood and/or Fecal RBC
Occult Blood vs. Fecal RBC
Occult Blood: Detects hemoglobin in stool
Fecal RBC: Tests for intact RBCs in stool
Associated with:
Gastrointestinal bleeding
Hemorrhoids
Colon cancer
Ulcers
Parasitic infections
Celiac Disease, Crohns Disease

20. Fecal pH Results vary with specific age groups
7-7.5 for adults and children
5-7 for neonates
Acidic stools are typically associated with the following:
Carbohydrate intolerance, such as lactose intolerances
Fat malabsorbtion
E. coli infections
Rotavirus infections
Strongly alkaline stools may indicate cholerheic enteropathy

21. Fecal WBC Evaluates acute, inflammatory cause of diarrhea
Indicates need for a stool culture

22. Fecal Meat Fibers
Indicator of malabsorption and pancreatic insufficiency

23. Charcot-Leyden Crystals
What are they?
Crystals found in stool that result from an enzyme released by damaged eosinophil cells which are present due to an allergy or parasitic infection.
Diagnostic uses
Indicator of possible parasitic infection
Other inflammatory or allergic condition such as eosinophilic gastroenteritis

24. Complete Stool Exam w/Ova and Parasite
Includes all tests found in a complete stool exam plus the following:
Fecal Concentration
Fecal Trichrome Stain

25. Qualitative Fecal Fat Steatorrhea Patient preparation:
Possible biological causes
Olestra: not since 2003
Orlistat
Patient preparation:
Patient should not use suppositories, mineral oils, or any other oil based products before collection of sample.
Patient should also avoid taking castor oil, bismuth, Metamucil and oily salad dressings for 1 week prior to testing.

26. Qualitative Fecal Fat Cont….
Test Includes:
Neutral Fecal Fat
Positive results indicate:
Deficiency of pancreatic enzymes
Small bowel disease
Aids in diagnosis of malabsorption and/or maldigestion
Split Fecal Fat
Impaired bile secretion
Inadequate adsorption of nutrients

27. Fecal Reducing Substance
Test is not performed at SRHC
sent out to Labcorp of America
Reference Range:
Normal: <0.25 g/dL
Trace: g/dL
Increased: >0.50 g/dL
Use: Detect malabsorption of primarily sucrase and lactase

28. Total cost of testing Complete stool exam
$600.40
Complete stool exam with Ova and Parasite
$828.70
How much will insurance pay?
Depends on insurance and diagnosis
What if patient has no insurance?
Payment is usually patient’s responsibility

29. Laboratory recommendations
A complete stool exam is not indicated in every instance of diarrhea
Pick and choose what tests are necessary when dealing with acute diarrhea based on patient history
Often see orders for CDA, WBC, culture
Do not order C. difficile culture
Tell the outpatient to disregard orders for stool testing if he/she no longer has diarrhea