Significant bacteriuria is associated with dementia, incontinence of faeces and of urine in long-stay hospital patients. Bacteriuria in these patients is a fluctuating condition: it occurred in 47% of an initially sterile control group during the course of a year. Management with urinary antiseptics and an initial course of antibiotics is more successful than antibiotics on demand. However, since the condition is so fluctuating, it is doubtful if any treatment is usually needed other than the prevention of faecal incontinence.