Measurement of the 5-hydroxyindoleacetic acid/creatinine ration in the urine of patients with coeliac disease.

Urinary excretion of 5-hydroxyindoleacetic acid and creatinine has been measured in 8-hour collections from adult patients with coeliac disease, and results have been compared with a group of healthy adult controls. Results were expressed as 5-HIAA/creatinine and significantly higher values of this ratio were found in patients with coeliac disease. Measurement of this ratio is a non-invasive technique which is useful in selecting patients with suspected coeliac disease for further investigation.