According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV TR) published by the American Psychiatric Association, the criteria for diagnosing a patient with bulimia are:
* Recurrent episodes of binge eating. An episode of binge eating is characterized by both of the following:
o Eating, in a fixed period of time, an amount of food that is definitely larger than most people would eat under similar circumstances. Mainly eating binge foods.
o A lack of control over eating during the episode: a feeling that one cannot stop eating or control what or how much one is eating.
* Recurrent inappropriate compensatory behavior to prevent weight gain, such as: self-induced vomiting; misuse of laxatives, diuretics, or other medications; fasting; excessive exercise.
* Triggers include periods of stress, traumatic events, and self-evaluation of body shape and weight.
* These symptoms may occur after every meal, on a daily basis, or once every few months.
* The disturbance does not occur exclusively during episodes of anorexia nervosa.
There are two sub-types of bulimia nervosa:
* Purging type bulimics self-induce vomiting (usually by triggering the gag reflex or ingesting emetics such as syrup of ipecac) to rapidly remove food from the body before it can be digested, or use laxatives, diuretics, or enemas.
* Non-purging type bulimics (approximately 6%-8% of cases) exercise or fast excessively after a binge to offset the caloric intake after eating. Purging-type bulimics may also exercise or fast, but as a secondary form of weight control.
The onset of bulimia nervosa is often during adolescence (between 13 and 20 years of age) and many cases have previously suffered obesity, with many sufferers relapsing in adulthood into episodic binging and purging even after initially successful treatment and remission.
Bulimia nervosa can be difficult to detect, compared to anorexia nervosa, because bulimics tend to be of average or slightly above or below average weight. Many bulimics may also engage in significantly disordered eating and exercising patterns without meeting the full diagnostic criteria for bulimia nervosa.