I just made my own. I bought a mini notebook and pen (small enough to go in a handbag or coat pocket) and just wrote down the time and everything I ate/ drank. I had a kind of shorthand for symptoms, and used a number from 1-10 to see how bad it was. I also wrote down what pills I'd taken (ie did I need painkillers that day? What dose of pred was I on?).
It was really useful, after a few months I looked back and wrote down everything that didn't give me symptoms, from there I worked out what did. And when I changed meds, we could see what impact it had had.
GI Monitor by Wellapps.com is a good one, they have it for iPhone and Blackberry. You can log pain levels, stool, stress level, meals, missed medications and add custom symptoms like fatigue, etc.
I didn't get on with the two I tried, my symptoms vary so much through the day but neither app let you add different pain levels etc for different times, you had to choose an average or overall for the day. But if you tend to have stable symptoms (if you have a bad day, it's the whole day) then the GI monitor is good.
at first i printed off some pages from the CCFA website. it lets you list what you eat, your symptom and the times it occurs. then i just got a notebook and did the same thing because it was easier to carry in my purse.