Main Line Health Laboratories (MLHL) performs stool cultures and tests for Clostridium difficile toxin, rotavirus, giardia antigen, white blood cells (WBCs), pH, reducing substances and fecal fat. We maintain critical values for stool cultures, ova and parasite examinations, and occult blood tests; standard stool-collection procedures for these three tests are provided here.

Stool culture

All specimens are examined for presence of Salmonella, Shigella, Campylobacter and E. coli O157.

Instructions to the patient

  1. Obtain the appropriate collection container from MLHL.
  2. For each test ordered, collect a specimen equal to or greater in size than a large walnut, or equal to or greater than about two teaspoons (5–10 grams) of liquid. Screw the lid tightly on the container.
  3. Label the collection container with your (the patient's) full name—exactly as it appears on the test requisition—and the date and time the specimen was collected.
  4. Disposable diapers are too absorbent and therefore not acceptable for culture.
  5. If possible, bring the specimen to your physician's office, if instructed to do so, or to an MLHL collection facility within one hour of passage; but the specimen will be accepted within 24 hours of passage if kept refrigerated.

Ova and parasite examination (O&P) using the Para-Pak™ system

Note: Liquids in pink-capped vials and blue-capped vials are poisonous. Keep out of reach of children.

An O&P exam cannot be performed on a specimen that contains antacids, barium, bismuth, antidiarrheal medication or oily laxatives. Be sure that the patient has not ingested any of these substances.

Instructions to the Patient:

  1. Obtain the appropriate collection containers.
  2. Collect a specimen equal to or greater in size than two large walnuts, or equal to or greater than two tablespoons (10–20 grams) of liquid. Collect in a clean, dry container.
  3. Transfer the specimen to the pink and blue capped vials. Fill each vial to the fill line, as directed in the package instructions. Fill both vials. Mix well. Please screw lids tightly on each vial.
  4. Label the collection container with your (the patient's) full name—exactly as it appears on the test requisition—and date and time the specimen was collected.
  5. If possible, bring the specimen to your physician’s office, if instructed to do so, or to an MLHL collection facility as soon as possible so that testing can be performed. Vials will be accepted for up to one week after specimen collection.

Occult blood test

Physician instructions for Hemoccult® SENSA® occult blood kits

The Hemoccult SENSA test is a rapid, convenient and qualitative method of detecting fecal occult blood, which may be indicative of gastrointestinal disease. Patients should follow the patient instructions below at least 7 days prior to and continuing through the test period. Physicians may elect not to put patients on the recommended dietary restrictions. Roughage in the diet can increase test accuracy by helping uncover "silent" lesions that bleed intermittently.

Instructions to the patient

Avoid seven days prior to and during the test period:

  • Aspirin or other nonsteroidal anti-inflammatory drugs

Avoid 72 hours prior to and during the test period:

  • Vitamin C in excess of 250 mg per day (from all sources, dietary and supplemental)
  • Red meat (beef, lamb), including processed meats and liver
  • Raw fruits and vegetables (especially melons, turnips and horseradishes)

Specimen Collection:

Hemoccult SENSA test requires only a small fecal specimen. The specimen is applied to the guaiac paper of the Hemoccult SENSA slide as a thin smear using the applicator stick provided. Hemoccult SENSA slides may be prepared and packaged when dry (wait three to five minutes) and returned to your office. Slides may be prepared and stored for up to 14 days at room temperature 15° to 30° C (59° to 86° F) before they are referred to MLHL. Please be sure to label each specimen with the patient’s full name and date of collection.

Fecal specimens should not be collected if hematuria or obvious rectal bleeding, such as from hemorrhoids, is present. Premenopausal women must be instructed to avoid collecting fecal specimens during or in the first three days after a menstrual period.

Since bleeding from gastrointestinal lesions may be intermittent, fecal specimens for testing should be collected from three consecutive bowel movements or three bowel movements closely spaced in time. To increase the probability of detecting occult blood, separate samples should be taken from two different sections of each fecal specimen.

Hemoccult SENSA slide tests should be packaged and referred to MLHL in the same manner as any other specimen.