Carrots can cause gas and bloating in some people who are sensitive. They are on the list of "gas producing veggies."
Even non-IBS people have troubles with carrots, celery, onions, cauliflower... -- you may have to experiment to see what causes it. That's why keeping a food diary is important. You see what foods keep popping up around your symptoms that might be triggers. Remember that sometimes the trigger happens nearly right away - and sometimes it can take up to 24 hours.