Fecal pH test
A fecal pH test (or faecal pH test) is one where a specimen of feces is tested for acidity in order to diagnose a medical condition. Human feces is normally alkaline. An acidic stool can indicate a digestive problem such as lactose intolerance or a contagion such as E. coli or rotavirus.
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.