Oh I'd like to add that the lump or whatever it is, is not visible. It's only something I can feel. Especially when standing
Your description suggest bulging of perineum when you are constipated. This can develop into a problem and you should avoid constipation by proper hydration. It would be unlikely that you have developed a rectocele or perineocele at you age but it is possible. A gynecological exam would be able to tell. J. Kyle Mathews, MD