Bladder calculi complicating intermittent catheterization.

Bladder calculi occurred as a late complication in 4 male patients who performed satisfactorily clean, intermittent catheterization. The mechanism for stone formation in each case was a hair introduced into the bladder, which served as a nidus for incrustation. Patients on intermittent catheterization, particularly male subjects with impaired tctile discrimination, should be instructed to observe diligently for and avoid adherence of hairs to the catheter to prevent this complication.