Mom (63) had a hysterectomy 30 years ago. She had blood in underwear this morning, then blood when wiping after using RR. Anyone know why?

Could be hemorrhoids, a bladder cyst, an infected gland--don't worry until you see the doc.

Probably nothing serious. This happens. I had chemo blisters all through chemo and beyond and they'd burst and bleed. One more lovely side effect of chemo. I've had them on and off since, dr says that's normal. Nothing 'healed up' the same.

https://www.health.harvard.edu/womens-health/postmenopausal-bleeding-dont-worry-but-do-call-your-doctor

Another possibility is a UTI

If she pushes too hard can cause fissures that bleed a little or like said hemorrhoids. But you really need to watch and if she still is showing blood, lets say Monday, you need to get her to a doctor.

Idontknowitall, this is something you need to discuss with your Mom's primary doctor.

Hopefully it is something as simple as a hemorrhoid issue. https://www.mayoclinic.org/diseases-conditions/hemorrhoids/symptoms-causes/syc-20360268