Rumination syndrome

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Rumination syndrome
Classification and external resources
A post-prandial manometry of a patient with rumination syndrome showing intra-abdominal pressure. The "spikes" are characteristic of the abdominal wall contractions responsible for the regurgitation in rumination.
ICD-10	P92.1, F98.2
ICD-9	307.53
DiseasesDB	34255
MedlinePlus	001539
eMedicine	article/916297
MeSH	D019959

Rumination syndrome, or Merycism is a severely under-diagnosed chronic eating disorder,^{[1][2][3][4][5][6][7]} which has been historically documented^[8] as affecting only infants, young children, and people with cognitive disabilities. Recently however, it has been diagnosed in increasing numbers of otherwise healthy adolescents and adults. Individuals with the syndrome experience postprandial^[9] regurgitation after most or every meal, without the retching, nausea, heartburn, odours, aches and pains that are normally associated with vomiting. Rumination syndrome presents itself in a variety of ways, especially when comparing an afflicted cognitively healthy adult to an infant or to a mentally disabled individual. Like most eating disorders, rumination can adversely affect normal functioning and the social lives of afflicted individuals.

There is little comprehensive data regarding Rumination syndrome in healthy individuals. Most of those afflicted with the disorder are very private about their rumination, and very few are correctly diagnosed due to the clinical similarities between Rumination syndrome and Bulimia Nervosa, including the acid induced erosion of the esophagus and teeth (Causing dental decay), halitosis, malnutrition, severe weight loss, and an unquenchable appetite. Some individuals may begin regurgitating within a minute following ingestion, and the full cycle of ingestion and regurgitation can mimic the binging and purging of bulimics.

[edit] Signs and symptoms

While the number and severity of the symptoms varies between individuals, repetitive regurgitation of undigested food (Rumination) after the start of a meal is present in all sufferers^[2][10]. In some individuals, the regurgitation is small and occurs over a long period of time following ingestion, and can be rechewed and swallowed, while in others the amount can be biluous and short lasting, and must be expelled. While some sufferers only experience symptoms following some meals, most are afflicted following any ingestion, from a single bite to a massive feast.^[11] However, some long-term sufferers will find a select couple of food or drink items that do not trigger a response (Though the individual ingredients of those items - Such as water - will trigger a response).

Unlike typical vomiting, the regurgitation of sufferers is often described as effortless and unforced. There is seldom nausea preceding the expulsion, and the undigested food lacks the bitter taste and odour of stomach acid and bile.^[1]

Symptoms can begin to manifest anywhere from during the actual ingestion of the meal, to 90 minutes thereafter. However, the more common range is between 30 seconds to one hour after the cessation of swallowing. Symptoms appear to cease when the ruminated contents become acidic.^[10]

Sufferers also commonly describe abdominal pain (38.1%), lack of fecal production or constipation (21.1%), nausea (17.0%), diarrhea (8.2%), bloating (4.1%), and dental decay (3.4%)^[2] as common symptoms in their day-to-day life. These symptoms are not necessarily prevalent during regurgitation episodes, and can happen at any time. Weight loss is often observed (42.2%) at an average loss of 9.6 kilograms, and is more common in cases where the disorder has gone undiagnosed for a longer period of time, though this may be expected of the nutrition deficiencies that often accompany the disorder as a consequence of its symptoms.

[edit] Causes

The cause of rumination syndrome is unknown. However, studies have drawn a correlation between many hypothesized causes and the history of patients with the disorder. In infants and the cognitively impaired, the disease has normally been attributed to over and under stimulation from parents and caregivers, causing the individual to seek self-gratification and self-stimulus due to the lack or abundance of external simulii. The disorder has also commonly been attributed to a bout of illness, or a period of stress in the individual's recent past, and to changes in medication.

In adults and adolescents, hypothesized causes generally fall into one of either category: Habit induced, and trauma induced. Habit induced individuals generally have a past history of bulimia nervosa or of intentional regurgitation (magicians and professional regurgitators, for example), which though initially self-induced, forms a subconscious habit which can continue to manifest itself outside the control of the affected individual. Trauma induced individuals generally describe an emotional or physical injury (such as recent surgery, psychological distress, concussions, deaths in the family, etc.) which preceded the onset of rumination, often by several months.^[2]

[edit] Diagnosis

Rumination syndrome is diagnosed based on a complete history of the individual sufferer. Costly and invasive studies such as gastroduodenal manometry and esophageal PH testing are unnecessary and will often aid in misdiagnosis. Based on typical clinical features, it has been proposed that the following criteria be used in the diagnosis of rumination syndrome:^[2]

• At least 6 weeks over the previous 12 months of recurrent regurgitation of recently ingested food which:
  1. Begins within 30 minutes postprandially
  2. Is associated with either reswallowing or expulsion of food
  3. Stops within 90 minutes of onset, or when regurgitant becomes acidic
  4. Is not associated with mechanical obstruction
  5. Does not respond to standard treatment for gastroesophageal reflux disease
  6. Is not associated with nocturnal symptoms

In adults, the syndrome is diagnosed further by the absence of classical or structural diseases of the gastrointestinal system. Supportive criteria to the diagnosis of rumination include:^[10]

• Regurgitant is not sour or acidic tasting
• Regurgitant is generally odourless, and never smells of bile
• The act is effortless, or at most preceded by a belching sensation. There is no retching preceding the regurgitation.
• The act is not associated with nausea or heartburn

[edit] Differential diagnosis

Rumination syndrome in adults is a complicated disorder whose symptoms can mimic those of several other gastroesophogeal disorders and diseases. The following conditions are especially prevalent amongst the misdiagnosis of rumination.

Bulimia nervosa, amongst adults and especially adolescents, is by far the most common (mis)diagnosis patients will hear during their experiences with rumination syndrome. This is due to the similarities in symptoms to an outside observer - "vomiting" (purging) following food intake (binging) - which in long term sufferers may include ingesting copious amounts to offset malnutrition (followed by a hasty retreat to the washroom), and a lack of willingness to expose their condition and its symptoms. Patients visit an average of five physicians over 2.75 years before reaching being correctly diagnosed with rumination syndrome.^[12] While it has been suggested that there is a connection between rumination and bulimia^[12][4], unlike bulimia, Rumination is not self-inflicted. Adult and adolescent rumination sufferers are generally well aware of their gradually increasing malnutrition, but are unable to control the reflex. In contrast, bulimic patients intentionally induce vomiting, and seldom reswallow food.

Gastroparesis is another common misdiagnosis, particularly in patients that exhibit the additional symptoms of rumination syndrome. Like rumination syndrome, patients suffering from gastroparesis often bring up food following the ingestion of a meal. Unlike rumination, gastroparesis causes vomiting (In contrast with regurgitation) of food within the stomach which is not being digested further. This vomiting occurs several hours after the meal is ingested, is preceded by nausea and retching, and has the bitter or sour taste typical of vomit.^[11]

[edit] Pathophysiology

Rumination syndrome is a poorly understood disorder, and a number of theories have speculated the mechanisms that cause the regurgitation, which is a unique symptom to this disorder. While no theory has gained a consensus, some are more notable and widely published than others.

The most widely documented mechanism is that the ingestion of food causes gastric distention (stretching), which is followed by abdominal compression and the simultaneous relaxation of the Lower esophageal sphincter (LES). This creates a common cavity between the stomach and the oropharynx that allows the partially digested material to return to the mouth. There are several offered explanations for the sudden relaxation of the LES^[13]:

• A learned voluntary relaxation - Common in past or current bulimics. While this relaxation may be voluntary, the overall process of rumination may still be involuntary.
• Relaxation due to intra-abdominal pressure - Which would make abdominal compression the primary mechanism.
• An adaptation of the belch reflex - Most commonly described. The swallowing of air immediately prior to regurgitation causes the activation of the belching reflex which triggers the relaxation of the LES.

[edit] Treatment

There is presently no known cure for rumination. Proton pump inhibitors (PPI's) and other medications have been used to little or no effect^[14]. Treatment is different for infants and the mentally handicapped than for adults and adolescents of normal intelligence. Amongst infants and the cognitively disabled, behavioral and mild aversive training has shown to cause improvement in most cases. Aversive training involves associating the ruminating behavior with negative results, and rewarding good behavior and eating. Placing a sour or bitter taste on the tongue when the individual begins the movements or breathing patterns typical of his or her ruminating behavior is the generally accepted method for aversive training.

In patients of normal intelligence, rumination is not an intentional behavior and is weened using diapgragmatic breathing techniques to counteract the urge to regurgitate. Alongside reassurance, explanation and habit reversal, patients are trained to keep their diaphragms contracted prior to and during rumination, thus preventing the muscle and breathing actions required for regurgitation, and effectively eliminating it with practise.^[14][15][16]

[edit] Prognosis

Supportive therapy and diaphragmatic control was shown to cause improvement in 56% of cases, and total cessation of symptoms in 30% (For a total of 86% of cases showing change for the better) in one study of 54 adolescent, non-disabled patients who were followed up 10 months after initial treatments.^[2]

[edit] Epidemiology

Age distribution at diagnosis. (Chial, Camilleri, Williams, Litzinger, Perrault. Pediatrics [2003];111;159)

Rumination disorder primarily affects infants and the cognitively handicapped. Amongst the latter, it is described with almost equal prevalence among infants (6-10% of the population) and adults (8-10%)^[1][17]. In mentally healthy infants, it typically occurs within the first 3–12 months of age and can lead to the child becoming malnourished. While rumination syndrome may begin in childhood or infancy, adults may also experience the symptoms of this chronic disorder. Its occurrence within the general population is largely unknown, due to the privacy of those afflicted, and the improper diagnosis of most sufferers.

Studies have shown a mostly female predominance^[18][2] for the condition. The typical age of adolescent onset is 12.9 ± 0.4, with males affected sooner than females (11.0 ± 0.8 for males versus 13.8 ± 0.5 for females).^[6]

The lack of a large study base has produced little evidence concerning the impact of race and hereditary causes in rumination syndrome. There is no known ethnic prevalence. Very few non-white patients have been documented at this point, and no conclusion on the impact of race and genes has been drawn, although case reports involving entire families with rumination exist.^[19]

[edit] History

The term Rumination is derived from the Latin word "ruminare", which means to chew the cud. The chewing of cud by animals such as cows, goats, and giraffes is considered normal behavior. These animals are known as ruminants. Rumination in humans is not ordinary behavior. First described in ancient times, and mentioned in the writings of Aristotle, rumination syndrome was first clinically documented in 1618 by Italian anatomist Fabricus ab Aquapendende, who wrote of the symptoms in a patient of his. ^{[19] [20]}

Amongst the earliest cases of rumination was that of a physician in the nineteenth century, Charles-Édouard Brown-Séquard, who acquired the condition as the result of experiments upon himself. As a way of evaluating and testing the acid response of the stomach to various foods, the doctor would swallow sponges tied to a string, then intentionally regurgitate them to analyze the contents. The result of these experiments was the doctor eventually regurgitating his meals habitually by reflex.^[21]

Numerous case reports were written before the twentieth century, but were influenced greatly by the methods and thinking used in that time. By the early twentieth century, it was becoming increasingly evident that rumination presented itself in a variety of ways in response to a variety of conditions.^[20] Although still considered a disorder of infancy and cognitive disability at that time, the difference in presentation between infants and adults was well established. ^[19]

Studies of rumination in otherwise healthy adults became decreasingly rare starting in the 1900's, and many published reports analyzing the syndrome in mentally healthy patients appeared thereafter. While the base of patients to examine has gradually increased as more and more people come forward with their symptoms, awareness of the condition by the medical community is still limited.^[22]

[edit] References

[edit] External links

• http://www.mayoclinic.org/rumination-syndrome/
• WedMD article on Rumination disorder