Rumination disorder may be diagnosed when a person deliberately brings food back up into the mouth and either rechews and reswallows it or spits it out.
Rumination disorder is sometimes called merycism. It is a disorder most commonly found in infants, and associated with mental retardation . During rumination, previously eaten food is intentionally brought back into the mouth. Sometimes the child spits it out, but in other cases, the food is rechewed and reswallowed. The regurgitation is not caused by a medical condition. In many cases, the child has had an illness associated with vomiting that occurs before the onset of rumination disorder. Rumination has also been observed in severe cases of eating disorders among teenagers as well as adults.
Causes and symptoms
There is no general agreement on the causes of rumination disorder. In infants, it is thought to be caused by a lack of nurturing or physical contact. The child's rumination may represent an attempt to stimulate or soothe him- or herself. Biological factors are also being explored as possible causes of rumination disorder.
The symptoms of rumination include both the regurgitation of food and, in infants, the effort made to regurgitate that food. In infants, the attempts to bring up food can include putting fingers in the mouth, sucking on the tongue, and arching the back. When food is brought up, the cheeks expand and appear puffed. Sometimes an observer can detect the rechewing; the person often appears to take pleasure in the act. The person's breath may have a foul or sour odor. Some infants, especially those who have just begun ruminating, will expel most or all of the regurgitated food from their mouths. When this expulsion occurs, it is often mistaken for normal infant vomiting. As an infant continues to ruminate, he or she often learns to keep more and more of the regurgitated food in the mouth.
Rumination disorder occurs primarily in infants. The onset usually occurs before the infant's first birthday. The disorder is also more common in people with mental retardation. The onset of rumination disorder is typically later in mentally retarded patients, however; it may not appear until puberty or even the early adult years. Rumination disorder is rare and thought to occur more often in males than in females. People who have anorexia nervosa or bulimia nervosa may begin to ruminate only in adult life. One report found that up to 20% of people with bulimia may ruminate.
The Diagnostic and Statistical Manual of Mental Disorders , fourth edition, text revision ( DSM-IV-TR ), which is the standard reference work for mental health professionals, gives only three general criteria for diagnosing rumination disorder. The first is that the person's behavior of deliberately bringing up and rechewing food must have lasted for at least a month. The regurgitation and rechewing must happen after a period of time in which the person did not ruminate. In addition, the rumination cannot result from a medical condition such as esophageal reflux. In addition, the manual specifies that the rumination cannot be associated with anorexia or bulimia.
Rumination disorder may be difficult to diagnose. One reason for this difficulty is that infants or adults who do not expel any of their regurgitated food can often be identified only by a puffing of the cheeks when the food is in the mouth or by an unpleasant breath odor. In addition, because many people and infants who ruminate find the experience a positive and pleasurable one, there are no physical signs of discomfort to bring the disorder to the attention of caretakers or others.
Some experts disagree with the statement of the Diagnostic and Statistical Manual that a diagnosis of rumination disorder cannot be made if the rumination is associated with anorexia or bulimia. These experts maintain that diagnosing and treating rumination disorder in patients who have other eating disorders is important for the sake of the patient's health.
Treatment for rumination disorder depends on the cause of the behavior. Infants who are thought to ruminate because of a lack of affection may be fed by someone other than their mother or father. This person can be a replacement while their parents receive treatment themselves. Other approaches involve therapy and parenting education to create a stronger bond between the parents and the child.
The treatment of adult patients includes giving them chewing gum to use when rumination might normally occur. Other researchers have found that giving mentally retarded adults filling meals may reduce rumination. Often, treating such eating disorders as anorexia or bulimia helps to resolve the rumination that may be associated with those disorders. Behavior modification techniques that help a patient to unlearn the ruminating behavior have also been used.
In many cases, rumination that begins in infancy stops on its own. The disorder should be treated, however, because infants with untreated rumination disorder are at risk of malnutrition and death caused by dehydration. Treatments for rumination disorder are generally very effective. Treatment of associated eating disorders in adults is generally regarded as successful.
There is no known way to prevent rumination disorder. It is possible, however, that a strong parent-child bond may reduce the possibility of the disorder occurring in infants.
American Psychiatric Association Diagnostic and Statistical Manual of Mental Disorders. 4th ed. text revised. Washington DC: American Psychiatric Association, 2000.
Sadock, Benjamin J. and Virginia A. Sadock, eds. Comprehensive Textbook of Psychiatry. 7th edition. Philadelphia: Lippincott Williams and Wilkins, 2000.
Weakley, Melinda M., Theodore A. Petti, George Karwisch. "Case Study: Chewing Gum Treatment of Rumination in an Adolescent with an Eating Disorder." Journal of the American Academy of Child and Adolescent Psychiatry 36, no. 8 (August 1997):1124-1128.
American Academy of Pediatrics. 141 Northwest Point Boulevard, Elk Grove Village, IL 60007-1098. (847) 434-4000. <www.aap.org> .
Tish Davidson, A.M.