I honestly don't do anything without my colon that I did with my colon, in terms of diet. I have no other health issues, my annual blood work is fine, albeit a low Vitamin D which I do supplement. I eat a cup of plain yogurt every day but I have been doing that the majority of my life and long before I was diagnosed with UC. I eat fairly healthy, lots of fresh fruits and vegetables, limit bread, and eat lean protein when I do eat meat. I drink 20oz of coffee in the morning then nothing until I hit the gym. I can out drink anyone when I' exercising but find during the work day I get most of my fluid intake via food. Breakfast and lunch consist of lots of fresh fruit high in water content.
Since we are very individual I think the best place for you to start is with a thorough CBC to see if you do need supplementing with either B or D. I wouldn't just take something because I thought I needed it, but that's just me. Your fluid intake is also going to be highly individual, based on your body's needs.