Value of urinary simple phenol and indican determinations in the diagnosis of the stagnant loop syndrome.

The urinary excretion of phenol, p-cresol, and indican was determined in 7 patients with the stagnant loop syndrome, 26 patients with coeliac disease, chronic pancreatitis, and partial gastrectomy, and 18 control patients. The mean excretion of the compounds in the patients with the stagnant loop syndrome and in the control patients, respectively, was 77 and 2.3 mg/24 h of phenol (p less than 0.05), 164 and 39.5 mg/24 h of p-cresol (n.s.), and 369 and 41.5 mg/24 h of indican (p less than 0.01). When applied as diagnostic tests for the stagnant loop syndrome, the phenol excretion showed 2 false negative results, the p-cresol excretion 3 false negative and 2 false positive results, and the indican excretion 6 false positive results. The combined use of phenol and indican determinations eliminated the number of false positive results with the indican test, and was found most useful as screening procedure. Determination of phenol and indican in a 24-hour urine sample is likely to provide a simple method for selecting patients with signs of abnormal bacterial colonization in the small intestine for more detailed investigations.