My mother is 90, has dementia and is now bowel incontinent. How can I prepare her to travel by air?

Sandy, someone with dementia will face orientation challenges after the flight; her dementia might cause confusion and she could become very unsettled during and after the flight.

Is there any way you can avoid this flight?

Assuming that the journey is absolutely necessary - and I can't imagine that you'd be doing this for the sheer fun of it, so it must be, but I admit I'd love to know why - then you could talk to the airline and see if their planes have any space set aside for medical emergencies and the like that you could use. The airport will have facilities for people with disabilities, which usually have enough space for changing; so do that at the last possible moment. And, obviously, in the days running up to the journey avoid those foods you know produce exciting results - like tomatoes and raisins and so on.

I don't know if something like Immodium or codeine prophylactically might help, but DO NOT do this without first seeking medical approval.

Why are you thinking about taking her on a plane?