Fecal pH test

Fecal pH test
Synonyms	faecal pH test, stool acidity test
LOINC	2755-7

A faecal pH test is one where a specimen of faeces is tested for acidity in order to diagnose a medical condition.

The pH of human faeces is variable but the average is pH 6.6 (acidic) for normal faeces.^[1][2] A lower faecal pH (very acidic stool) can indicate a digestive problem such poor absorption of carbohydrates or fats,^[3] lactose intolerance,^[4] an infection such as E. coli or rotavirus, or overgrowth of acid-producing bacteria (such as lactic acid bacteria).

Test procedure

The test is fast and can be performed in a doctor's office. A patient must not be receiving antibiotics. At least half a milliliter of feces is collected, and a strip of nitrazine paper is dipped in the sample and compared against a color scale. A pH of less than 5.5 indicates an acidic sample.^[5]

Results

Unhealthy individuals with a higher or lower pH rate have been observed having a higher mortality rate. A high alkaline pH rating is associated with the body's inability to create enough acid along with undigested food.^[6]

References

1. "010991: Stool pH". Health Matters. Retrieved 2023-07-06.
2. Procházková, Nicola; Laursen, Martin F.; La Barbera, Giorgia; Tsekitsidi, Eirini; Jørgensen, Malte S.; Rasmussen, Morten A.; Raes, Jeroen; Licht, Tine R.; Dragsted, Lars O.; Roager, Henrik M. (December 2024). "Gut physiology and environment explain variations in human gut microbiome composition and metabolism". Nature Microbiology. 9 (12): 3210–3225. doi:10.1038/s41564-024-01856-x. ISSN 2058-5276. PMC 11602727.
3. Ben (2019-02-09). "What is Stool PH? High and low values | Lab results explained". Retrieved 2024-11-28.
4. "Point-of-Care Testing, Fecal pH Measurement". Archived from the original on 2007-07-03. Retrieved 2007-02-07.
5. "eMedicine - Gastroenteritis, Bacterial : Article by Jennifer Lynn Bonheur, MD". 13 June 2023.
6. Osuka A, Shimizu K, Ogura H, Tasaki O, Hamasaki T, Asahara T, Nomoto K, Morotomi M, Kuwagata Y, Shimazu T (July 2012). "Prognostic impact of fecal pH in critically ill patients". Critical Care. 16 (4): R119. doi:10.1186/cc11413. PMC 3580696. PMID 22776285.

See also

• Stool test