Jejunoscopic lactose provocation.

A new method for testing lactose intolerance was developed. The examination is performed by jejunoscopy using lactose dilution for provocation and sucrose for control. Macroscopic and microscopic changes in the jejunal mucosa are examined after administration of solutions. The results of this study demonstrated that lactose administration causes prompt change in the jejunal mucosa in cases of lactose intolerance but had no effect in cases of lactose tolerance. Administration of sucrose did not result in any change. This method is effective in proving lactose intolerance and may be useful to elucidate the pathogenesis of this disorder.