Perianal pruritus sometimes is based on demonstrable and specific causative factors: fungus infections, psoriasis, contact or atopic dermatitis, disorders of the gastrointestinal tract itself, or systemic disease. However, in a certain proportion of the cases investigation fails to show any of the usual causes, such cases of "essential" pruritus often eventually being labelled as psychosomatic. Doubtless some are, but pruritus in patients without demonstrable organic disease may often be due to anatomical peculiarities which make cleansing of the perianal skin difficult: the presence of abnormally voluminous and redundant radiating perianal folds, or of mild rectal prolapse. In these patients, fecal staining of underclothes and residual fecal material in the perianal folds are often seen in spite of repeated wipings. Proper hygiene could be maintained if the patients were instructed to cleanse themselves as usual after the bowel movement, and follow this by wiping with toilet tissue to which several drops