DIARRHEA

WHAT TO ORDER

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

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

DIARRHEA

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

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

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

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

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

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

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

 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

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

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

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)

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

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

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

Complete Stool Exam Cont…

Tests not included: 

C. Diff Toxin

(CDA) or Culture  Stool Culture 

Yesinia

Culture  O&P  Reducing substances

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

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

Fecal WBC

  Evaluates acute, inflammatory cause of diarrhea Indicates need for a stool culture

Fecal Meat Fibers

 Indicator of malabsorption and pancreatic insufficiency

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

Complete Stool Exam w/Ova and Parasite

 Includes all tests found in a complete stool exam plus the following:  Fecal Concentration  Fecal Trichrome Stain

Qualitative Fecal Fat

 Steatorrhea  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.

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  Positive results indicate:  Impaired bile secretion  Inadequate adsorption of nutrients

Fecal Reducing Substance

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

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

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