While my mother, age 99, was in the hospital for 2 weeks she developed bowel incontinence. She had never had that problem before. Any ideas why?

Hospitals tend to create more problems than they cure, especially when elders are involved. Do not judge mom's behaviors as the new norm until she's been back home in her own environment for a couple of months. In the meantime, get her disposable briefs and take her to the bathroom every 2 hours on a schedule.

Is she on a laxative because they can make it an urgency she can't hold. Did the staff take her to the bathroom regularly or did they allow her to go in Depends. It may be you need to retrain her. Start taken her every 2 hrs. Figure out when #2 is done. Like after dinner...then take her then. Like said she is 99.

I should also just check whether she was being given laxatives that she doesn't normally need. I have known them to be dished out without an awful lot of thought, and/or continued after they were strictly necessary; and this especially happens with people who aren't taking an active interest in their own medications - the nurse says "here you are" and hands over the little paper cup of pills, and the lovely compliant little old lady obediently swallows them.

Best practice says you should tell the person what the medication is and what it's for, every time, but best practice never seems to take much reality into account.

I'd sort of rather hope it's something like this than that she's picked up a hospital bug.

What was she in the hospital for?
Did she receive antibiotics during her stay in hospital?
Has her stool changed; that is to say is consistency loose, explosive? Has her diet changed?

I would discuss with doctor whether she might have clostridium difficile, and whether a testing of stool is in order.

Do understand that he living to this age without incontinence makes her somewhat unusual. But this is a sudden change. For me, as an RN, every patient was a mystery. Look on this as "What has changed here". Wish you the best.

It really depends (no pun intended).

My dad had an accident. He wore Depends and maybe still does but can mostly go to the toilet.