1. If she is chronically constipated, discuss it with her doctor and ask for advice on diet and gentle laxatives (go carefully). It could also be that this is a lifelong habit and her muscle tone is in a shocking state, in which case perhaps advice on pelvic floor exercises might help.
2. Discreetly accompany her when she goes to the bathroom. You don't stand and stare, obviously; you pretend you're not there and intervene at the strategic moments. This is also helpful because you can guide hand washing afterwards.
Is she only doing this in the bathroom (with after effects, yikes) or is it when she's just sitting around any old where?
I'd get her the anti strip clothing from one of the adaptive clothing suppliers like Silverts or Buck & Buck and supervise her in the bathroom. And make sure her bowel movements aren't hard and causing her distress.
2. Discreetly accompany her when she goes to the bathroom. You don't stand and stare, obviously; you pretend you're not there and intervene at the strategic moments. This is also helpful because you can guide hand washing afterwards.
Is she only doing this in the bathroom (with after effects, yikes) or is it when she's just sitting around any old where?