Bathroom access in China- ulcerative colitis

Hey all, I’m going to China next month (Chengdu, Chongqing, and Guiyang) and I’d like some tips/help with bathroom access.

I was diagnosed with ulcerative colitis about while back, and though it’s well managed and under control, traveling and new food, routines, schedules might make it act up.

Where is it common to find free public restrooms? I understand that I should carry some toilet paper with me. Is it common for food establishments to have restrooms?

Any help would be much appreciated.