Define Diagnostic Criteria for Bulimia Nervosa?

1. Recurrent episodes of binge eating. An episode of binge eating is characterized by both of the following

a) Eating, in a discrete period of time (e.g., within any 2 hour period), an amount of food that is definitely larger than most people would eat during similar period of time under similar circumstances.

b) A sense of lack of control over eating during an episode e.g., a feeling that one cannot stop eating or control what or how much one is eating.

2. Recurrent inappropriate compensatory behaviour to prevent weight gain such as self-induced vomiting, misuse of laxatives diuretics or other medications; fasting; or excessive exercise.

3. The binge eating and inappropriate compensatory behaviours both occur, on an average, at least twice a week for 3 months.

4. Self-evaluation is unduly influenced by body shape and weight.

5. The disturbance does not occur exclusively during episodes of anorexia nervosa.

Bulimia nervosa, is further characterized as the purging type or the non-purging type. In the purging type, during a current episode of bulimia nervosa, the person regularly engages in self-induced vomiting or the misuse of laxatives, diuretics or enemas. In the non-purging type, during an episode of bulimia nervosa, the person uses other inappropriate compensatory behaviours, such as fasting or excessive exercise as mentioned earlier, but does not regularly engage in self-induced vomiting or use of laxatives, diuretics etc. Diagnostic criteria for bulimia nervosa require that at least twice a week for 3 months patient must have episode of consuming a very large amount of food, which a normal person is not capable of eating. There must be evidence that binge eating, which is central to the diagnosis, is followed by self-induced vomiting which is seen in 80% to 90% of persons with bulimia nervosa. Disturbed body image is also an essential feature. Further, in bulimia, weight fluctuations are common. Patients even though thin, may be well within 15% of the ideal weight, some may even be overweight as informed earlier. About 50% have normal menstrual cycle. Physical findings are generally minimal. It is important to look for scars from self-mutilation in every suspected case.