['Constipation and lower urinary tract symptoms (LUTS) very frequently occur in the elderly, and several reports have suggested that dysfunction in either one of these systems may affect the other. Most studies correlating rectal and bladder dysfunction, however, have been carried out in children or young women.', 'To examine the effect of alleviating constipation on LUTS in the elderly.', 'Fifty-two patients aged 65-89 (mean 72 +/- 13) years with chronic constipation and LUTS participated in this prospective cohort study. Before treatment of constipation was initiated and on their monthly visits, patients completed a questionnaire regarding their constipation pattern, urinary symptoms, sexual function and mood, and underwent urinalysis. Urinary tract anatomy and residual urine were evaluated by abdominal ultrasound at the commencement and completion of the study. Patients were followed up for 4 months.', 'Treatment of constipation increased the number of weekly defecations from 1.5 +/- 0.9 to 4.7 +/- 1.2 (p < 0.001). Patients spent less time on the toilet (25 +/- 2.1 versus 63 +/- 1.9 min, p < 0.0001). Fewer patients reported urgency (16 versus 34, p < 0.001), frequency (25 versus 47, p < 0.001) and burning sensation during urination (6 versus 17, p < 0.05). There was improvement in the scoring of urgency, frequency and burning sensation (from a baseline of 52 to 126, 131 and 95, respectively, p < 0.001). Urinary stream disturbances improved in 32 of the 52 patients (p < 0.001). Residual urine volume decreased from 85 +/- 39.5 to 30 +/- 22.56 ml (p < 0.001). There was also a significant decrease in the number of patients with bacteriurial events (5 versus 17, p < 0.001), and an improvement in sexual activity and mood (p < 0.05).'] Does alleviating constipation in the elderly improve lower urinary tract symptoms?