Objective Manometric Criteria for the Rumination Syndrome
Objective Manometric Criteria for the Rumination Syndrome
To search for objective impedance–pressure criteria for the rumination syndrome, we compared impedance–pressure patterns in patients with clinically diagnosed rumination and compared these with patterns found in patients with GERD. Our results demonstrate that it is indeed possible to use impedance–manometry to distinguish patients with the rumination syndrome from GERD patients with regurgitation as clearly distinct patterns are seen. All patients with the rumination syndrome, but none of the patients with GERD, exhibited gastric pressure peaks >30 mm Hg during stationary manometry and ambulatory manometry.
Until now, rumination has been difficult to diagnose clinically. The current diagnostic criteria that are defined in the ROME III criteria are mainly based on the presence of postprandial regurgitation. Therefore, several problems arise with regard to the rumination syndrome. First, the syndrome is relatively rare and physicians therefore often do not recognize the symptoms of rumination as such. Second, patients with GERD often present with complaints of regurgitation. As reflux episodes often occur in the postprandial period, complaints of the rumination syndrome are often mistaken for symptoms of GERD. Even though the clinical presentation of rumination and GERD is similar, the management of these two groups of patients is vastly different. Rumination patients are treated with behavioral feedback therapy, whereas GERD patients are treated by PPI and ultimately anti-reflux surgery. There is thus a great need for an adequate diagnostic tool to diagnose the rumination syndrome.
We demonstrated that all patients with rumination syndrome exhibit gastric pressure peaks >30 mm Hg during combined manometry–impedance. However, 30% of all rumination episodes were characterized by pressure peaks <30 mm Hg. The latter suggests that rumination episodes can also be induced by pressure peaks <30 mm Hg. A cut-off value below 30 mm Hg would therefore enhance the detection of rumination episodes. However, GERD patients can exhibit gastric pressure peaks up to 30 mm Hg and a significant overlap between the pressure peaks of patients with the rumination syndrome and patients with GERD was observed. Therefore, a cut-off value <30 mm Hg would also identify GERD patients as having the rumination syndrome. As all patients with the rumination syndrome exhibit pressure peaks >30 mm Hg, we consider a gastric pressure peak of >30 mm Hg as the optimal cut-off for rumination episodes.
For this study, we used combined stationary HRM and pH-impedance monitoring as well as combined ambulatory manometry and pH-impedance monitoring. Similar findings were observed with these two techniques, which suggest that both techniques are able to diagnose the rumination syndrome and ambulatory measurements do not provide additional information. Furthermore, our proposed criteria can be applied to ambulatory manometry–impedance and stationary HRM–impedance, which suggest that the techniques are equally effective in diagnosing the rumination syndrome. If both techniques are available in a center, other factors, such as duration of the investigation, the availability of an investigation room and the preference of the physician and patient will determine the technique that will be used.
Three distinct rumination variants have been identified in this study, which could, in theory, be caused by different pathophysiological mechanisms. In patients with primary rumination, the etiology is least clear, as no event could be identified that preceded a rumination episode using HRM–impedance monitoring. Previous studies have suggested that rumination is a learned behavior caused by an unpleasant gastrointestinal sensation. Moreover, the initial trigger for a patient's behavior could even have disappeared before the diagnosis is made. The pathophysiology of primary rumination therefore remains to be elucidated and additional studies are warranted. During secondary rumination, a gastroesophageal reflux episode precedes the rumination episode. The latter suggests that the unpleasant sensation of gastric content in the esophagus could trigger a rumination event. In patients with supragastric belch-associated rumination, a supragastric belch precedes the rumination episode. The results from our HRM–impedance study demonstrated that the intragastric pressure rises during the expulsion of air. The latter suggests that this forceful expulsion of air also forces out gastric content into the esophagus. Therefore, supragastric belches are the most probable cause of the rumination episodes in these patients and their belching behavior has most likely existed before the rumination episodes occurred.
The identification of three different rumination variants could, in theory, affect the treatment of rumination patients. The cornerstone of treatment of the rumination syndrome is currently an explanation of a patient's condition, after which a patient is referred for behavioral therapy or biofeedback training. The latter two treatments are believed to compete with the urge to regurgitate and have yielded positive outcomes in previous studies. Previous studies have also demonstrated that patients with isolated belching symptoms caused by supragastric belching respond favorably to behavioral therapy performed by a speech therapist. The latter suggests that patients who exhibit supragastric belch-associated rumination would also benefit from behavioral therapy. However, in patients with secondary rumination, rumination episodes appear to be triggered by reflux episodes. Biofeedback could, in theory, decrease a patient's response to the unpleasant sensation of a reflux episode. PPI could also reduce the number of rumination episodes by decreasing the severity of heartburn. However, reflux episodes will still occur despite PPI and weakly acidic reflux could still trigger secondary rumination episodes. Therefore, fundoplication could, in theory prevent the trigger for rumination episodes in these patients. However, there is no evidence that supports the use of fundoplication in patients with the rumination syndrome and clinicians should be hesitant with performing anti-reflux surgery in patients with secondary rumination.
A limitation of this study is the limited size of our study population. However, the results from our study show a statistically significant difference between patients with the rumination syndrome and patients with GERD, and we therefore believe that the size of the population in this study is sufficient for the development of a classification based on physiological measurements. Furthermore, all known variants of the rumination syndrome have been included in this study and all these variants show similar outcomes with regard to the cut-off value of 30 mm Hg.
In conclusion, combined pressure–impedance criteria can differentiate rumination patients from GERD patients with predominant symptoms of regurgitation. We propose that the diagnosis of the rumination syndrome is based on demonstration of reflux events extending to the proximal esophagus that are closely associated with an abdominal pressure increase >30 mm Hg. In addition, three subtypes of the rumination syndrome have been identified, which include primary rumination, secondary rumination, and supragastric belch-associated rumination.
Discussion
To search for objective impedance–pressure criteria for the rumination syndrome, we compared impedance–pressure patterns in patients with clinically diagnosed rumination and compared these with patterns found in patients with GERD. Our results demonstrate that it is indeed possible to use impedance–manometry to distinguish patients with the rumination syndrome from GERD patients with regurgitation as clearly distinct patterns are seen. All patients with the rumination syndrome, but none of the patients with GERD, exhibited gastric pressure peaks >30 mm Hg during stationary manometry and ambulatory manometry.
Until now, rumination has been difficult to diagnose clinically. The current diagnostic criteria that are defined in the ROME III criteria are mainly based on the presence of postprandial regurgitation. Therefore, several problems arise with regard to the rumination syndrome. First, the syndrome is relatively rare and physicians therefore often do not recognize the symptoms of rumination as such. Second, patients with GERD often present with complaints of regurgitation. As reflux episodes often occur in the postprandial period, complaints of the rumination syndrome are often mistaken for symptoms of GERD. Even though the clinical presentation of rumination and GERD is similar, the management of these two groups of patients is vastly different. Rumination patients are treated with behavioral feedback therapy, whereas GERD patients are treated by PPI and ultimately anti-reflux surgery. There is thus a great need for an adequate diagnostic tool to diagnose the rumination syndrome.
We demonstrated that all patients with rumination syndrome exhibit gastric pressure peaks >30 mm Hg during combined manometry–impedance. However, 30% of all rumination episodes were characterized by pressure peaks <30 mm Hg. The latter suggests that rumination episodes can also be induced by pressure peaks <30 mm Hg. A cut-off value below 30 mm Hg would therefore enhance the detection of rumination episodes. However, GERD patients can exhibit gastric pressure peaks up to 30 mm Hg and a significant overlap between the pressure peaks of patients with the rumination syndrome and patients with GERD was observed. Therefore, a cut-off value <30 mm Hg would also identify GERD patients as having the rumination syndrome. As all patients with the rumination syndrome exhibit pressure peaks >30 mm Hg, we consider a gastric pressure peak of >30 mm Hg as the optimal cut-off for rumination episodes.
For this study, we used combined stationary HRM and pH-impedance monitoring as well as combined ambulatory manometry and pH-impedance monitoring. Similar findings were observed with these two techniques, which suggest that both techniques are able to diagnose the rumination syndrome and ambulatory measurements do not provide additional information. Furthermore, our proposed criteria can be applied to ambulatory manometry–impedance and stationary HRM–impedance, which suggest that the techniques are equally effective in diagnosing the rumination syndrome. If both techniques are available in a center, other factors, such as duration of the investigation, the availability of an investigation room and the preference of the physician and patient will determine the technique that will be used.
Three distinct rumination variants have been identified in this study, which could, in theory, be caused by different pathophysiological mechanisms. In patients with primary rumination, the etiology is least clear, as no event could be identified that preceded a rumination episode using HRM–impedance monitoring. Previous studies have suggested that rumination is a learned behavior caused by an unpleasant gastrointestinal sensation. Moreover, the initial trigger for a patient's behavior could even have disappeared before the diagnosis is made. The pathophysiology of primary rumination therefore remains to be elucidated and additional studies are warranted. During secondary rumination, a gastroesophageal reflux episode precedes the rumination episode. The latter suggests that the unpleasant sensation of gastric content in the esophagus could trigger a rumination event. In patients with supragastric belch-associated rumination, a supragastric belch precedes the rumination episode. The results from our HRM–impedance study demonstrated that the intragastric pressure rises during the expulsion of air. The latter suggests that this forceful expulsion of air also forces out gastric content into the esophagus. Therefore, supragastric belches are the most probable cause of the rumination episodes in these patients and their belching behavior has most likely existed before the rumination episodes occurred.
The identification of three different rumination variants could, in theory, affect the treatment of rumination patients. The cornerstone of treatment of the rumination syndrome is currently an explanation of a patient's condition, after which a patient is referred for behavioral therapy or biofeedback training. The latter two treatments are believed to compete with the urge to regurgitate and have yielded positive outcomes in previous studies. Previous studies have also demonstrated that patients with isolated belching symptoms caused by supragastric belching respond favorably to behavioral therapy performed by a speech therapist. The latter suggests that patients who exhibit supragastric belch-associated rumination would also benefit from behavioral therapy. However, in patients with secondary rumination, rumination episodes appear to be triggered by reflux episodes. Biofeedback could, in theory, decrease a patient's response to the unpleasant sensation of a reflux episode. PPI could also reduce the number of rumination episodes by decreasing the severity of heartburn. However, reflux episodes will still occur despite PPI and weakly acidic reflux could still trigger secondary rumination episodes. Therefore, fundoplication could, in theory prevent the trigger for rumination episodes in these patients. However, there is no evidence that supports the use of fundoplication in patients with the rumination syndrome and clinicians should be hesitant with performing anti-reflux surgery in patients with secondary rumination.
A limitation of this study is the limited size of our study population. However, the results from our study show a statistically significant difference between patients with the rumination syndrome and patients with GERD, and we therefore believe that the size of the population in this study is sufficient for the development of a classification based on physiological measurements. Furthermore, all known variants of the rumination syndrome have been included in this study and all these variants show similar outcomes with regard to the cut-off value of 30 mm Hg.
In conclusion, combined pressure–impedance criteria can differentiate rumination patients from GERD patients with predominant symptoms of regurgitation. We propose that the diagnosis of the rumination syndrome is based on demonstration of reflux events extending to the proximal esophagus that are closely associated with an abdominal pressure increase >30 mm Hg. In addition, three subtypes of the rumination syndrome have been identified, which include primary rumination, secondary rumination, and supragastric belch-associated rumination.
