Stool Samples

Specimen types you should send:

  • The specimen of choice is diarrheal stool. (Please note that some patients may have taken anti-diarrheal treatments).
  • A rectal swab is only recommended and permissible for infants.
  • A single specimen of diarrheal stool should suffice to find any routinely screened for bacterial pathogen, including Salmonella, Shigella, Campylobacter and E.coli species.
  • For ova, cyst and parasite (OCP) testing please note that administration of barium, oil, magnesium or crystalline compounds can lead to unsatisfactory results. Please delay specimen collection for at least 5 days after administration of such agents.

How to Collect the Sample

  • Faecal material is placed into the depicted container with the aid of the plastic spoon.

Labeling

  • See Pathology Sample Labelling Policy. Label the specimen with patient information (First Name, Surname, DoB, location, physician, time and date) and also fill in those details on the request form.
  • On request form indicate the investigations required (e.g. M/C&S, OCP other special studies e.g. Yersinia culture)
  • Very importantly give a good history on the request form (e.g. "foreign travel to..." or "watery diarrhoea after holidays in India" or "diarrhoea on ward after course of ceftazidime" or "immunocompromised patient"). This information guides the laboratory to select any supplementary tests where appropriate.
  • If the patient had a positive stool culture previously or clinically a specific isolate is suspected (e.g. E. coli O157 causing Haemolytic-Uraemic Syndrome) please put this information on the request form.

List of routine culture tests for faecal samples

Note that other organisms will be cultured for on grounds of clinical details or specific request on form.

  • Salmonella/shigella
  • Campylobacter
  • E. coli O157 (for suspected cases an enrichment culture will be set up in addition).

Which Container does it go in?

 Image of container suitable for stool samples

Above is an image of a container suitable for a stool sample.

Transport

  • If the specimen is not transported immediately for bacterial culture refrigerate.
  • If there is any anticipated delay of >48hr for a C. difficile toxin study refrigerate.
  • Please note that stool samples taken to demonstrate trophozoites of Entamoeba histolytica - for diagnosis of amoebic dysentery - must reach the laboratory within 30mins. No time limit for ova, cysts and non-trophozoite forms of parasites.
 

Page Reviewed: 15/05/14 | Updated by: Kevin Roberts