As I read it, from Chengdu to Danba by bus takes about 9-10 hours.

Yes, the buses are equipped with reclining seats and you won't feel uncomfortable for the long distance journey. However, no toilet is available on the bus. And the buses will stop for 3-4 times, 10-15min or so every time for passengers to go to toilets and have a short rest.

Hi! In May 2017, I took the bus and arrived at 3.30 pm, 7 hours. The bus condition was nice. Toilet was inside but locked! Well, the driver made 2 stops, the first one for buffet lunch which was 20 yuan, and the second was for a toilet. Hope this would help!