A new method for chemical analysis of faeces.

By using a centriflo membrane cone filter it has become possible to obtain an ultrafiltrate from a 24-h stool specimen. In this faecal fluid several clinical chemical parameters were analysed, such as pH, osmolality, creatinine, sodium, potassium, calcium, magnesium, chloride, bicarbonate, phosphate and lactate. Reference intervals for these substances were obtained in healthy individuals. The data of this control group were compared to those of patients with diarrhoea due to active inflammatory bowel disease, irritable bowel syndrome, lactose intolerance and persons with an ileostomy.