Clinical relevance of lysozyme in the faeces.

To elucidate the value of faecal lysozyme determination in the differential diagnosis of patients with atypical abdominal complaints, stool samples of healthy controls, patients with irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) were analysed. Faecal lysozyme concentration in healthy controls ranged from 0 to 6 mg/l with a mean of 3 mg/l. Patients with IBS had similar faecal lysozyme levels. In contrast, faecal lysozyme concentrations in patients with IBD were increased (range 6 to 104 mg/l). The difference between patients with IBS and IBD was highly significant (P less than 0.001). The determination of faecal lysozyme concentration may provide a useful test in the work-up of patients with abdominal complaints. In addition, the faeces lysozyme concentration appeared to be an objective parameter of the inflammatory activity of IBD in 11 patients investigated.