in your age is likely due to menopause
setting in however Next time you have the same problem do get an ultrasound
done to just make sure no other pathology related to uterus or cervix is underlying. When your oestrogen levels fall it can lead to constipation
and hence chronic straining can lead to formation of hemorrhoids which is the most common cause of bright red bleeding. Consult a gynaecologist who can start you on hormones to pacify your symptoms if very troublesome.