Use a Japanese-style toilet bidet. Bolt-on, cold water ones are less than $50. (You get used to the cold water, surprisingly.) Warm water ones, less than $100. Top-of-the-line (entire) toilets, $4000.
I have hemorrhoids and bought a bidet about 2 years ago. I have not had a single flair up since I started using it. I cannot recommend them highly enough.
We got what's supposed to be a good one of the add-on kind, and I expected to really like it, but instead I hate it. It makes the toilet quite a bit harder to clean and I don't see any way that it's not just spraying old shit-flecks and piss drops at me, which will surely find their way to the nozzle with some regularity.
I think I'd really like a proper, separate bidet, but it turns out I hate the bolt-on kind.