Question about hygiene and large backsides?

Hello. Thank you for reading.

My girlfriend has always had a very pronounced backside, even before I met her, and has always been very cautious about her hygiene in that reason as such.

After we moved in together, she started gaining some weight (mostly unintentionally), and as one would imagine, this has led to her butt getting quite a lot bigger. At first, this was not a problem to her (in fact, she quite enjoyed the effects it had on me), but she hasn't really stopped gaining weight since she started, which is leading to a situation where the added fat is making it harder for her to wipe.

So my question is:

To those with a (very) large backside who have encountered issues with wiping, what are some ways to overcome this issue/make the issue easier to manage?

For reference, my girlfriend is currently pushing 400 at about 5'5''. Not sure of the particular measurement of her butt, but it is one of her most prominent features. Neither of us are very flexible, nor are we very active at the moment.

I have considered getting a bidet for home use, as I think that would be helpful, but that doesn't help with outside of the house. I'm particularly interested in any methods that would help in public situations.

Thank you in advance for the advice!
3 years