I, like you, used to use the Canasa only when flaring or feeling close to a flare. I decided after my last flare about a year ago to use it every night. I've been fine since. I have little or no trouble keeping it in all night comfortably so it doesn't affect me sleeping.
Canasa, at least for me, also has the added benefit of also being a good warning sign for me. Usually I expel it first thing in the morning and it's the same color as it went in. But if I felt a little bit off the day before or ate something I shouldn't have, it comes out a kind of blackish-purple as if something was amiss and it was doing its job. Then I take it really light on the food and it seems to heal everything quickly.
Anyhow, while getting to a doctor is always a good idea, you might want to use the Canasa nightly no matter what, especially if is doesn't give you diarrhea in and of itself. This is especially important because you're not bleeding yet and you can cut it off at the pass.
Good luck and FEEL BETTER!!!