I am like you. I never feel that great most of the time but only call into work sick when in severe flare. In the last 7 years I have averaged about 3 - 4 weeks off sick per year. All taken in one go when flaring. I also work evenings as this is when I feel most well but of course when you are not getting home until 12.30, bed at about 1 then up in the morning to take kids to school it is hard going.
I live in the UK and applied for disability, not so that I could give up work but maybe drop a couple of shifts per week so I wasn't as tired all the time but I was refused. They wrote to me and said they do not give disability benefits to people who have diorrhea or so they could be near a toilet all the time. Two fingers up to them, if they only knew what living with this disease was all about. If it was only a bit of diorrhea I wouldn't be trying to claim benefits. My cousin who also has UC, has had a brain hemmorhage (sp!) which is still leaking blood and has another annurism in her brain which has not yet burst but is being monitored was also refused, she is appealing but not holding out much hope.