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