pH, Stool

Stool pH is dependent in part on fermentation of sugars. Colonic fermentation of normal amounts of carbohydrate sugars and production of fatty acids accounts for the normally slightly acidic pH.

This test is used to detect carbohydrate and fat malabsorption and to evaluate small intestinal disaccharidase deficiencies. High (alkaline) in increased protein breakdown, secretory diarrhea without food intake, colitis, villous adenoma and possibly with use of antibiotics. Alkaline stool pH may be a risk factor for colorectal cancer. Low (acidic) in intestinal lactase deficiency, high lactose intake, decreased absorptionof carbohydrates, and decreased fat absorption. A stool pH of <6 is suggestive evidence of sugar malabsorption.

Stool, 3-5 grams Refrigerated at 2-8 °C

Collect specimen in leak-proof container, diapers containing stool are not acceptable. Stool should be collected fresh, free from urine contamination, and tested promptly, within 2 hours of collection. Delay in testing, improper storage, or exposure to air can alter stool pH.

6.0 - 8.0