(1) A preventive and / or a remedy for lower urinary tract diseases such as inflammation in the lower urinary tract, cystitis (interstitial cystitis, etc.) and urethritis; (2) an agent for improving bladder compliance and / or bladder capacity; and (3) an agent for protecting bladder mucosa and / or bladder epithelial cells and / or promoting the regeneration thereof; each containing an EP4 agonist. An EP4 agonist is useful in ameliorating symptoms of lower urinary tract diseases such as (1) frequent urination, (2) urgency of urination, (3) pain in the reproductive organs and / or lower urinary tract (for example, bladder pain, urinary tract pain, vulvar pain, vaginal pain, scrotal pain, perineal pain, pelvic pain, etc.) and / or (4) discomfort in the reproductive organs and / or lower urinary tract. Among all, a selective EP4 agonist is useful as a preventive and / or remedy for lower urinary tract diseases having no side effect.