I have body dysmorphic disorder and I got CBT based therapy for it. It was helpful, but I found that I was still bulimic. I had hoped helping deal with my body image issues would help, but it only dealt with my anxiety-behaviours (covering my nose, always wearing hoods and hats, avoiding daylight, big coats, taking years to get ready, mirror avoidance etc) and not really my body image. I didn't believe I wasn't hideous, it just helped me realise my fears were possibly out of proportion.
I began to recover from bulimia and maintained a healthy weight but recently my weight has risen quite dramatically (I'm not sure why, I think it's a medication I take as I had been keeping a food diary and not eating more) and I have relapsed. I've never been underweight but I am now quite overweight. I'm vomiting a few times a day.
I am not quite bulimic as I don't really binge but I purge normal (or somewhat excessive but generally under 1000kcals) amounts of food and abuse laxatives. It's probably ED-NOS but was diagnosed as bulimia as they assumed (without asking, which I wish they would have done) that I binged. But as I've relapsed, I've also noticed my anxiety behaviours of BDD returning so I think they are related.
Would be interested to hear your experiences.