Here again is one of those different eating disorders. Purging disorder is not specified in the DSM (Diagnostic and Statistical Manual of Mental Disorders) as an "official" eating disorder. It is very much like Bulimia Nervosa, but someone with this disorder does not fit the purging part of the diagnosis.
With this disorder, the person will purge small amounts of food in some way. Either through bulimia signs such as self-induced vomiting, anorexia symptoms such as exercise addiction, use of laxatives or diuretics, other anorexia symptoms such as fasting or some other compensatory behavior like orthorexia.
Difficult to detect
The person probably does not maintain a significantly low or high weight. They are of normal or nearly normal body weight. Thus the reason it can be difficult to detect.
Signs and Symptoms
The symptoms are very similar to those of bulimia nervosa, as are the effects of eating disorders and health issues associated with the disorder. Please take a look at those sections for more information.
Purging, by the way, isn't just defined as throwing up. It can also be purging in terms of using laxatives and diuretics, or other medications to rid the body of nutrients. It can also include over exercise.
Avoiding dealing with feelings
As with the other eating disorders, the goal with this disorder is to avoid dealing with feelings. Literally, the person may purge everything they eat in a day. Alternatively, they may only purge after experiencing something emotional. But remember, the hallmark is ... what makes this different from bulimia nervosa ... binging behaviors are not present.