Thoracoabdominal Wall Motion-Guided Biofeedback Treatment of Abdominal Distension: A Randomized Placebo-Controlled Trial.

BACKGROUND & AIMS: Abdominal distention results from abdominophrenic dyssynergia (ie, diaphragmatic contraction and abdominal wall relaxation) in patients with disorders of the gut-brain interaction. This study aimed to validate a simple biofeedback procedure, guided by abdominothoracic wall motion, for treating abdominal distension. METHODS: In this randomized, parallel, placebo-controlled trial, 42 consecutive patients (36 women and 6 men; ages 17-64 years) with meal-triggered visible abdominal distension were recruited. Recordings of abdominal and thoracic wall motion were obtained using inductance plethysmography via adaptable belts. The signal was shown to patients in the biofeedback group, who were taught to mobilize the diaphragm. In contrast, the signal was not shown to the patients in the placebo group, who were given a placebo capsule. Three sessions were performed over a 4-week intervention period, with instructions to perform exercises (biofeedback group) or to take placebo 3 times per day (control group) at home. Outcomes were assessed through response to an offending meal (changes in abdominothoracic electromyographic activity and girth) and clinical symptoms measured using daily scales for 7 days. RESULTS: Patients in the biofeedback group (n = 19) learned to correct abdominophrenic dyssynergia triggered by the offending meal (intercostal activity decreased by a mean ± SE of 82% ± 10%, anterior wall activity increased by a mean ± SE of 97% ± 6%, and increase in girth was a mean ± SE of 108% ± 4% smaller) and experienced improved clinical symptoms (abdominal distension scores decreased by a mean ± SE of 66% ± 5%). These effects were not observed in the placebo group (all, P < .002). CONCLUSIONS: Abdominothoracic wall movements serve as an effective biofeedback signal for correcting abdominophrenic dyssynergia and abdominal distention in patients with disorders of the gut-brain interaction. ClincialTrials.gov, Number: NCT04043208.

Visible abdominal distension in functional gut disorders: Objective evaluation.

BACKGROUND: Visible abdominal distension has been attributed to: (A) distorted perception, (B) intestinal gas accumulation, or (C) abdominophrenic dyssynergia (diaphragmatic push and anterior wall relaxation). METHODS: A pool of consecutive patients with functional gut disorders and visible abdominal distension included in previous studies (n = 139) was analyzed. Patients (61 functional bloating, 74 constipation-predominant irritable bowel syndrome and 4 with alternating bowel habit) were evaluated twice, under basal conditions and during a self-reported episode of visible abdominal distension; static abdominal CT images were taken in 104 patients, and dynamic EMG recordings of the abdominal walls in 76, with diaphragmatic activity valid for analysis in 35. KEY RESULTS: (A) Objective evidence of abdominal distension was obtained by tape measure (increase in girth in 138 of 139 patients), by CT imaging (increased abdominal perimeter in 96 of 104 patients) and by abdominal EMG (reduced activity, i.e., relaxation, in 73 of 76 patients). (B) Intestinal gas volume was within ±300 ml from the basal value in 99 patients, and above in 5 patients, who nevertheless exhibited a diaphragmatic descent. (C) Diaphragmatic contraction was detected in 34 of 35 patients by EMG (increased activity) and in 82 of 103 patients by CT (diaphragmatic descent). CONCLUSIONS AND INFERENCES: In most patients complaining of episodes of visible abdominal distention: (A) the subjective claim is substantiated by objective evidence; (B) an increase in intestinal gas does not justify visible abdominal distention; (C) abdominophrenic dyssynergia is consistently evidenced by dynamic EMG recording, but static CT imaging has less sensitivity.

Abdominophrenic Dyssynergia: A Narrative Review.

Chronic bloating and abdominal distension are common and highly bothersome gastrointestinal symptoms. Although the differential diagnoses for bloating and distension are broad, these symptoms are frequently associated with disorders of the gut-brain interaction. Functional abdominal bloating may be a result of visceral hypersensitivity, whereas abdominal distension seems to be a somatic behavioral response associated with abdominophrenic dyssynergia, featuring diaphragmatic contraction and abdominal wall relaxation. We review the available literature regarding abdominophrenic dyssynergia and comment on its epidemiology, diagnosis, treatment, and avenues to address in the near future.

Evaluation of abdominal gas by plain abdominal radiographs.

BACKGROUND: Our aim was to determine the reliability of plain abdominal radiographs for the evaluation of abdominal gas content in patients with functional digestive symptoms. METHODS: Abdominal CT scan scout views, mimicking a conventional plain abdominal radiograph, were obtained from 30 patients both during episodes of abdominal distension and basal conditions. Physicians (n = 50) were instructed to rate the estimated volume of gas in the 60 images presented in random sequence using a scale graded from 0 to ≥600 ml. KEY RESULTS: The gas volumes estimated in the scout views differed from those measured by CT by a median of 90 (95% CI 70-102) ml, and the misestimation was not related to the absolute volume in the image. The accuracy of the observers, measured by their mean misestimation, was not related to their specialty or the training status (misestimation by 96 (95% CI 85-104) ml in staff vs 78 (70-106) ml in residents; p = 0.297). The accuracy was independent of the order of presentation of the images. Gas volume measured by CT in the images obtained during episodes of abdominal distension differed by a median of 39 (95% CI 29-66) ml from those during basal conditions, and this difference was misestimated by a median of 107 (95% CI 94-119) ml. The accuracy of these estimations was not related to the absolute gas volumes (R = -0.352; p < 0.001) or the magnitude of the differences. CONCLUSIONS & INFERENCES: Plain abdominal radiographs have limited value for the evaluation of abdominal gas volume in patients with functional gut disorders.

Benefit of extending the protocol for high resolution manometry according to the version 4.0 of the Chicago criteria. A multicenter study.

BACKGROUND: The last version of the Chicago Criteria for high resolution esophageal manometry proposes an expanded protocol including complementary maneuvers to improve the diagnostic yield of the exploration. Our aim was to determine the diagnostic gain of the CCv4.0 protocol compared to the CCv3.0 protocol. METHODS: All manometry recordings performed in 4 reference centers during the first 10 months after the implementation of the new protocol were retrospectively reviewed. The time spent to complete the protocol was measured, and the changes in diagnosis resulting from the new CCv4.0 were compared to CCv3.0. KEY RESULTS: From a total of 756 HRM performed, 606 studies could be properly analyzed. The duration of the studies was 18.3 ± 4.3 min. From these, 11.3 ± 3.4 min were spent to complete the CCv3.0 protocol, and 7.4 ± 3.6 min were spent for the remaining maneuvers. A discordant diagnosis between CCv3.0 and CCv4.0 was obtained in 12% of patients: 32% of patients with ineffective esophageal motility turned to normal motility; 24% of patients with esophagogastric junction outlet obstruction (EGJOO) turned to a non-obstructive disorder; and 1% of patients with an apparently normal EGJ relaxation, turned to an obstructive disorder. EGJOO according to CCv4.0 was more prevalent in patients referred for dysphagia (11%) than those referred for GERD (4%; p = 0.003). CONCLUSIONS AND INFERENCES: Prolongation of the time spent to complete the CCv4.0 protocol leads to a change in the diagnosis of 12% of patients. Clinically relevant changes are mainly related to the evaluation of EGJOO.

Síndrome de rumiación, revisión crítica / Rumination syndrome: Critical review

El síndrome de rumiación es un trastorno funcional caracterizado por la regurgitación involuntaria de los alimentos recientemente ingeridos desde el estómago hacia la boca, donde puede ser remasticados o expulsados. Desde el punto de vista clínico, se caracteriza por episodios repetidos de regurgitación de alimentos sin esfuerzo, con vómitos frecuentes como queja habitual. El mecanismo físico que genera los eventos de regurgitación depende de un proceso involuntario que altera las presiones abdominal y torácica, acompañado de una unión esofagogástrica permisiva. El diagnóstico del síndrome de rumiación es clínico: destaca la importancia de realizar una anamnesis exhaustiva sobre las características de los síntomas. Las pruebas complementarias se utilizan para corroborar el diagnóstico o descartar otra enfermedad orgánica. El tratamiento está enfocado a terapias conductuales como primera línea, reservando las terapias farmacológicas y quirúrgicas para casos refractarios.

Rumination syndrome is a functional disorder characterized by the involuntary regurgitation of recently swallowed food from the stomach into the mouth, from where it can be re-chewed or expelled. Clinically, it is characterized by repeated episodes of effortless food regurgitation. The most usual complaint is frequent vomiting. The physical mechanism that generates regurgitation events is dependent on an involuntary process that alters abdominal and thoracic pressures accompanied by a permissive oesophageal-gastric junction. The diagnosis of rumination syndrome is clinical, highlighting the importance of performing an exhaustive anamnesis on the characteristics of the symptoms. Complementary tests are used to corroborate the diagnosis or rule out organic pathology. Treatment is focused on behavioural therapies as the first line, reserving pharmacological and surgical therapies for refractory cases.

Rumination syndrome: Critical review. / Síndrome de rumiación, revisión crítica.

Rumination syndrome is a functional disorder characterized by the involuntary regurgitation of recently swallowed food from the stomach into the mouth, from where it can be re-chewed or expelled. Clinically, it is characterized by repeated episodes of effortless food regurgitation. The most usual complaint is frequent vomiting. The physical mechanism that generates regurgitation events is dependent on an involuntary process that alters abdominal and thoracic pressures accompanied by a permissive oesophageal-gastric junction. The diagnosis of rumination syndrome is clinical, highlighting the importance of performing an exhaustive anamnesis on the characteristics of the symptoms. Complementary tests are used to corroborate the diagnosis or rule out organic pathology. Treatment is focused on behavioural therapies as the first line, reserving pharmacological and surgical therapies for refractory cases.

A Fermented Milk Product Containing B. lactis CNCM I-2494 Improves the Tolerance of a Plant-Based Diet in Patients with Disorders of Gut-Brain Interactions.

Healthy, plant-based diets, rich in fermentable residues, may induce gas-related symptoms. The aim of this exploratory study was to assess the effects of a fermented milk product, containing probiotics, on the tolerance of a healthy diet in patients with disorders of gut-brain interactions (DGBI), complaining of excessive flatulence. In an open design, a 3-day healthy, mostly plant-based diet was administered to patients with DGBI (52 included, 43 completed) before and at the end of 28 days of consumption of a fermented milk product (FMP) containing Bifidobacterium animalis subsp. lactis CNCM I-2494 and lactic acid bacteria. As compared to a habitual diet, the flatulogenic diet increased the perception of digestive symptoms (flatulence score 7.1 ± 1.6 vs. 5.8 ± 1.9; p < 0.05) and the daily number of anal gas evacuations (22.4 ± 12.5 vs. 16.5 ± 10.2; p < 0.0001). FMP consumption reduced the flatulence sensation score (by -1.6 ± 2.2; p < 0.05) and the daily number of anal gas evacuations (by -5.3 ± 8.2; p < 0.0001). FMP consumption did not significantly alter the overall gut microbiota composition, but some changes in the microbiota correlated with the observed clinical improvement. The consumption of a product containing B. lactis CNCM I-2494 improved the tolerance of a healthy diet in patients with DGBI, and this effect may be mediated, in part, by the metabolic activity of the microbiota.

Abdominothoracic Postural Tone Influences the Sensations Induced by Meal Ingestion.

Postprandial objective abdominal distention is frequently associated with a subjective sensation of abdominal bloating, but the relation between both complaints is unknown. While the bloating sensation has a visceral origin, abdominal distention is a behavioral somatic response, involving contraction and descent of the diaphragm with protrusion of the anterior abdominal wall. Our aim was to determine whether abdominal distention influences digestive sensations. In 16 healthy women we investigated the effect of intentional abdominal distention on experimentally induced bloating sensation (by a meal overload). Participants were first taught to produce diaphragmatic contraction and visible abdominal distention. After a meal overload, sensations of bloating (0 to 10) and digestive well-being (-5 to + 5) were measured during 30-s. maneuvers alternating diaphragmatic contraction and diaphragmatic relaxation. Compared to diaphragmatic relaxation, diaphragmatic contraction was associated with diaphragmatic descent (by 21 + 3 mm; p < 0.001), objective abdominal distension (32 + 5 mm girth increase; p = 0.001), more intense sensation of bloating (7.3 + 0.4 vs. 8.0 + 0.4 score; p = 0.010) and lower digestive well-being (-0.9 + 0.5 vs. -1.9 + 0.5 score; p = 0.028). These results indicate that somatic postural tone underlying abdominal distention worsens the perception of visceral sensations (ClinicalTrials.gov ID: NCT04691882).

Recommendations of the Spanish Association of Neurogastroenterology and Motility (ASENEM) to restart the activity of gastrintestinal motility laboratories after the state of alarm called due to the Covid-19 pandemic. / Recomendaciones de la Asociación Española de Neurogastroenterología y Motilidad (ASENEM) para el reinicio de la actividad de los laboratorios de motilidad digestiva, tras el confinamiento por el estado de alarma decretado a raíz de la pandemia por COVID-19.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was responsible for the outbreak of the 2019 coronavirus disease (COVID-19), which is now considered as a pandemic. The prevention strategies adopted have included social distancing measures and the modification, reduction or interruption of a large proportion of routine healthcare activity. This has had a significant impact on the care provided in Gastrointestinal Motility Units. Having passed the peak, in terms of mortality and infections, a gradual reduction in transmission figures has been observed in Spain and other European countries. The risk of reactivation, however, remains high, so it is necessary to have a plan in place that allows healthcare centres to safely resume, for their patients and professionals, instrumental examinations linked to the management of motor pathology. Based on the available scientific evidence and the consensus of a panel of experts, the Spanish Association of Neurogastroenterology and Motility (ASENEM) has drawn up a series of practical recommendations, which have been adapted to the risks inherent in each activity. These include individual protection proposals, as well as organisational and structural measures, which are conceived to allow for the gradual resumption of examinations while minimising the possibility of contagion.

A Fermented Milk Product with B. Lactis CNCM I-2494 and Lactic Acid Bacteria Improves Gastrointestinal Comfort in Response to a Challenge Diet Rich in Fermentable Residues in Healthy Subjects.

BACKGROUND: Healthy plant-based diets rich in fermentable residues may induce gas-related symptoms. Our aim was to determine the potential of a fermented milk product with probiotics in improving digestive comfort with such diets. METHODS: In an open design, a 3-day high-residue diet was administered to healthy subjects (n = 74 included, n = 63 completed) before and following 28 days consumption of a fermented milk product (FMP) containing Bifidobacterium animalis subsp. lactis CNCM I-2494 and lactic acid bacteria. MAIN OUTCOMES: digestive sensations, number of daytime anal gas evacuations, and gas volume evacuated during 4 h after a probe meal. RESULTS: As compared to the habitual diet, the high-residue diet induced gas-related symptoms (flatulence score 4.9 vs. 1.2; p ≤ 0.0001), increased the daily number of anal gas evacuations (20.7 vs. 8.7; p < 0.0001), and impaired digestive well-being (1.0 vs. 3.4; p < 0.05). FMP consumption reduced flatulence sensation (by -1.7 [-1.9; -1.6]; p < 0.0001), reduced the number of daily evacuations (by -5.8 [-6.5; -5.1]; p < 0.0001), and improved digestive well-being (by +0.6 [+0.4; +0.7]; p < 0.05). FMP consumption did not affect the gas volume evacuated after a probe meal. CONCLUSION: In healthy subjects, consumption of a FMP containing B. lactis CNCM I-2494 and lactic acid bacteria improves the tolerance of a flatulogenic diet by subjective and objective criteria (sensations and number of anal gas evacuations, respectively).

Recomendaciones de la Asociación Española de Neurogastroenterología y Motilidad (ASENEM) para el reinicio de la actividad de los laboratorios de motilidad digestiva, tras el confinamiento por el estado de alarma decretado a raíz de la pandemia por COVID-19 / Recommendations of the Spanish Association of Neurogastroenterology and Motility (ASENEM) to restart the activity of gastrintestinal motility laboratories after the state of alarm called due to the Covid-19 pandemic

El coronavirus del síndrome respiratorio agudo severo tipo 2 (conocido por sus siglas en inglés, SARS-CoV-2) ha sido responsable del brote de la denominada enfermedad por coronavirus de 2019 (COVID-19), que ha llegado a tener la consideración de pandemia. Las estrategias adoptadas para su prevención han incluido medidas de distanciamiento social, así como la modificación, reducción o interrupción de gran parte de la actividad sanitaria habitual. Esto ha afectado de forma muy notable a la asistencia prestada en las Unidades de Motilidad Digestiva.Superado el pico de mortalidad y contagios por la infección, se ha observado durante las últimas semanas en España y otros países europeos una reducción paulatina en las cifras de transmisión. Sin embargo, el riesgo de reactivación sigue siendo alto, por lo que es necesario disponer de una planificación que permita a los centros sanitarios reiniciar con seguridad para pacientes y profesionales, las exploraciones instrumentales vinculadas al manejo de la patología motora. La Asociación Española de Neurogastroenterología y Motilidad (ASENEM) ha elaborado una serie de recomendaciones prácticas basadas en la evidencia científica disponible y en el consenso de un panel de expertos, y adaptadas a los riesgos inherentes a cada actividad. Se incluyen propuestas de protección individual, pero también medidas organizativas y estructurales, cuyo objetivo es permitir reanudar progresivamente las exploraciones, minimizando la posibilidad de contagio

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was responsible for the outbreak of the 2019 coronavirus disease (COVID-19), which is now considered as a pandemic. The prevention strategies adopted have included social distancing measures and the modification, reduction or interruption of a large proportion of routine healthcare activity. This has had a significant impact on the care provided in Gastrointestinal Motility Units. Having passed the peak, in terms of mortality and infections, a gradual reduction in transmission figures has been observed in Spain and other European countries. The risk of reactivation, however, remains high, so it is necessary to have a plan in place that allows healthcare centres to safely resume, for their patients and professionals, instrumental examinations linked to the management of motor pathology. Based on the available scientific evidence and the consensus of a panel of experts, the Spanish Association of Neurogastroenterology and Motility (ASENEM) has drawn up a series of practical recommendations, which have been adapted to the risks inherent in each activity. These include individual protection proposals, as well as organisational and structural measures, which are conceived to allow for the gradual resumption of examinations while minimising the possibility of contagion

Abdominal distension after eating lettuce: The role of intestinal gas evaluated in vitro and by abdominal CT imaging.

BACKGROUND: Some patients complain that eating lettuce, gives them gas and abdominal distention. Our aim was to determine to what extent the patients' assertion is sustained by evidence. METHODS: An in vitro study measured the amount of gas produced during the process of fermentation by a preparation of human colonic microbiota (n = 3) of predigested lettuce, as compared to beans, a high gas-releasing substrate, to meat, a low gas-releasing substrate, and to a nutrient-free negative control. A clinical study in patients complaining of abdominal distention after eating lettuce (n = 12) measured the amount of intestinal gas and the morphometric configuration of the abdominal cavity in abdominal CT scans during an episode of lettuce-induced distension as compared to basal conditions. KEY RESULTS: Gas production by microbiota fermentation of lettuce in vitro was similar to that of meat (P = .44), lower than that of beans (by 78 ± 15%; P < .001) and higher than with the nutrient-free control (by 25 ± 19%; P = .05). Patients complaining of abdominal distension after eating lettuce exhibited an increase in girth (35 ± 3 mm larger than basal; P < .001) without significant increase in colonic gas content (39 ± 4 mL increase; P = .071); abdominal distension was related to a descent of the diaphragm (by 7 ± 3 mm; P = .027) with redistribution of normal abdominal contents. CONCLUSION AND INFERENCES: Lettuce is a low gas-releasing substrate for microbiota fermentation and lettuce-induced abdominal distension is produced by an uncoordinated activity of the abdominal walls. Correction of the somatic response might be more effective than the current dietary restriction strategy.

Diagnosis and Treatment of Rumination Syndrome.

Rumination syndrome is a functional gastrointestinal disorder characterized by effortless postprandial regurgitation. The disorder appears uncommon, although only limited epidemiologic data are available. Awareness of the characteristic symptoms is essential for recognizing the disorder, and thus avoiding the long delay in diagnosis, that many patients experience. Although objective testing by postprandial esophageal high-resolution impedance manometry is available in select referral centers, a clinical diagnosis can be made in most patients. The main therapy for rumination syndrome is behavioral modification with postprandial diaphragmatic breathing. This clinical practice update reviews the pathophysiology, diagnosis, and treatment of rumination syndrome. Best Practice Advice 1: Clinicians strongly should consider rumination syndrome in patients who report consistent postprandial regurgitation. Such patients often are labeled as having refractory gastroesophageal reflux or vomiting. Best Practice Advice 2: Presence of nocturnal regurgitation, dysphagia, nausea, or symptoms occurring in the absence of meals does not exclude rumination syndrome, but makes the presence of it less likely. Best Practice Advice 3: Clinicians should diagnose rumination syndrome primarily on the basis of Rome IV criteria after an appropriate medical work-up. Best Practice Advice 4: Diaphragmatic breathing with or without biofeedback is the first-line therapy in all cases of rumination syndrome. Best Practice Advice 5: Instructions for effective diaphragmatic breathing can be given by speech therapists, psychologists, gastroenterologists, and other health practitioners familiar with the technique. Best Practice Advice 6: Objective testing for rumination syndrome with postprandial high-resolution esophageal impedance manometry can be used to support the diagnosis, but expertise and lack of standardized protocols are current limitations. Best Practice Advice 7: Baclofen, at a dose of 10 mg 3 times daily, is a reasonable next step in refractory patients.

Correction of Abdominal Distention by Biofeedback-Guided Control of Abdominothoracic Muscular Activity in a Randomized, Placebo-Controlled Trial.

BACKGROUND & AIMS: Abdominal distention is produced by abnormal somatic postural tone. We developed an original biofeedback technique based on electromyography-guided control of abdominothoracic muscular activity. We performed a randomized, placebo-controlled study to demonstrate the superiority of biofeedback to placebo for the treatment of abdominal distention. METHODS: At a referral center in Spain, we enrolled consecutive patients with visible abdominal distention who fulfilled the Rome III criteria for functional intestinal disorders (47 women, 1 man; 21-74 years old); 2 patients assigned to the placebo group withdrew and 2 patients assigned to biofeedback were not valid for analysis. Abdominothoracic muscle activity was recorded by electromyography. The patients in the biofeedback group were shown the signal and instructed to control muscle activity, whereas patients in the placebo received no instructions and were given oral simethicone. Each patient underwent 3 sessions over a 10-day period. The primary outcomes were subjective sensation of abdominal distention, measured by graphic rating scales for 10 consecutive days before and after the intervention. RESULTS: Patients in the biofeedback group effectively learned to reduce intercostal activity (by a mean 45% ± 3%), but not patients in the placebo group (reduced by a mean 5% ± 2%; P < .001). Patients in the biofeedback group learned to increase anterior wall muscle activity (by a mean 101% ± 10%), but not in the placebo group (decreased by a mean 4% ± 2%; P < .001). Biofeedback resulted in a 56% ± 1% reduction of abdominal distention (from a mean score of 4.6 ± 0.2 to 2.0 ± 0.2), whereas patients in the placebo group had a reduction of only 13% ± 8% (from a mean score of 4.7 ± 0.1 to 4.1 ± 0.4) (P < .001). CONCLUSIONS: In a randomized trial of patients with a functional intestinal disorder, we found that abdominal distention can be effectively corrected by biofeedback-guided control of abdominothoracic muscular activity, compared with placebo. ClincialTrials.gov no: NCT01205100.

Randomized, Placebo-Controlled Trial of Biofeedback for the Treatment of Rumination.

OBJECTIVES: We previously demonstrated that rumination is produced by an unperceived, somatic response to food ingestion, and we developed an original biofeedback technique based on electromyography (EMG)-guided control of abdomino-thoracic muscular activity. Our aim was to demonstrate the superiority of biofeedback vs. placebo for the treatment of rumination. METHODS: Randomized, placebo-controlled trial performed in a referral center. Consecutive patients who fulfilled the Rome III criteria for rumination (18 women, 6 men; 19-79 years age) were selected and all included in the study; 1 patient assigned to placebo withdrew because of an unrelated accident. Abdomino-thoracic muscle activity after a challenge meal was recorded by EMG. The patients in the biofeedback group were shown the signal and instructed to control muscle activity, whereas the patients in the placebo group were not shown the signal and were given oral simethicone. Each patient underwent 3 sessions over a 10-day period. MAIN OUTCOME: number of rumination events as measured by questionnaires for 10 consecutive days before and after intervention. RESULTS: Patients on biofeedback (n=12) but not on placebo (n=11) effectively learned to reduce intercostal activity (by 51±6% vs. 10±7% increment on placebo; P<0.001) and anterior wall muscle activity (by 52±4% vs. 9±2% increment on placebo; P<0.001). Biofeedback treatment resulted in a 74±6% reduction in rumination activity (from 29±6 before to 7±2 daily events after intervention) vs. 1±14% on placebo; P=0.001 (from 21±2 before to 21±4 daily events after intervention). CONCLUSIONS: Rumination can be effectively corrected by biofeedback-guided control of abdomino-thoracic muscular activity.

Biofeedback-guided control of abdominothoracic muscular activity reduces regurgitation episodes in patients with rumination.

BACKGROUND & AIMS: Rumination syndrome is characterized by effortless recurrent regurgitation of recently ingested food into the mouth, with consequent expulsion or re-chewing and swallowing. We investigated whether rumination is under volitional control and can be reversed by behavioral treatment. METHODS: We performed a prospective study of 28 patients who fulfilled the Rome criteria for rumination and had no organic disorders on the basis of a thorough evaluation. The diagnosis of rumination was confirmed by intestinal manometry (abdominal compression associated with regurgitation). Patients were trained to modulate abdominothoracic muscle activity under visual control of electromyographic recordings. Recordings were made after challenge meals, before training (baseline), and during 3 treatment sessions. Outcome was measured by questionnaires administered daily for 10 days before training, immediately after training, and at 1, 3, and 6 months after training. RESULTS: By the end of the 3 sessions, patients had effectively learned to reduce intercostal activity (by 50% ± 2%; P < .001 vs basal) and anterior wall muscle activity (by 30% ± 6%; P < .001 vs basal). Patients reported 27 ± 1 regurgitation episodes/day at baseline and 8 ± 2 episodes/day immediately after treatment. Regurgitation episodes decreased further to 4 ± 1 episodes at 6 months after training. CONCLUSIONS: Rumination is produced by an unperceived somatic response to food ingestion that disrupts abdominal accommodation and can be effectively corrected by biofeedback-guided control of abdominothoracic muscular activity.

Abdominothoracic mechanisms of functional abdominal distension and correction by biofeedback.

BACKGROUND & AIMS: In patients with functional gut disorders, abdominal distension has been associated with descent of the diaphragm and protrusion of the anterior abdominal wall. We investigated mechanisms of abdominal distension in these patients. METHODS: We performed a prospective study of 45 patients (42 women, 24-71 years old) with functional intestinal disorders (27 with irritable bowel syndrome with constipation, 15 with functional bloating, and 3 with irritable bowel syndrome with alternating bowel habits) and discrete episodes of visible abdominal distension. Subjects were assessed by abdominothoracic computed tomography (n = 39) and electromyography (EMG) of the abdominothoracic wall (n = 32) during basal conditions (without abdominal distension) and during episodes of severe abdominal distension. Fifteen patients received a median of 2 sessions (range, 1-3 sessions) of EMG-guided, respiratory-targeted biofeedback treatment; 11 received 1 control session before treatment. RESULTS: Episodes of abdominal distension were associated with diaphragm contraction (19% ± 3% increase in EMG score and 12 ± 2 mm descent; P < .001 vs basal values) and intercostal contraction (14% ± 3% increase in EMG scores and 6 ± 1 mm increase in thoracic antero-posterior diameter; P < .001 vs basal values). They were also associated with increases in lung volume (501 ± 93 mL; P < .001 vs basal value) and anterior abdominal wall protrusion (32 ± 3 mm increase in girth; P < .001 vs basal). Biofeedback treatment, but not control sessions, reduced the activity of the intercostal muscles (by 19% ± 2%) and the diaphragm (by 18% ± 4%), activated the internal oblique muscles (by 52% ± 13%), and reduced girth (by 25 ± 3 mm) (P ≤ .009 vs pretreatment for all). CONCLUSIONS: In patients with functional gut disorders, abdominal distension is a behavioral response that involves activity of the abdominothoracic wall. This distension can be reduced with EMG-guided, respiratory-targeted biofeedback therapy.

Mechanisms of postprandial abdominal bloating and distension in functional dyspepsia.

OBJECTIVE: Patients with irritable bowel syndrome and abdominal bloating exhibit abnormal responses of the abdominal wall to colonic gas loads. We hypothesised that in patients with postprandial bloating, ingestion of a meal triggers comparable abdominal wall dyssynergia. Our aim was to characterise abdominal accommodation to a meal in patients with postprandial bloating. DESIGN: A test meal (0.8 kcal/ml nutrients plus 27 g/litre polyethylenglycol 4000) was administered at 50 ml/min as long as tolerated in 10 patients with postprandial bloating (fulfilling Rome III criteria for postprandial distress syndrome) and 12 healthy subjects, while electromyographic (EMG) responses of the anterior wall (upper and lower rectus, external and internal oblique via bipolar surface electrodes) and the diaphragm (via six ring electrodes over an oesophageal tube in the hiatus) were measured. Means +/- SD were calculated. RESULTS: Healthy subjects tolerated a meal volume of 913±308 ml; normal abdominal wall accommodation to the meal consisted of diaphragmatic relaxation (EMG activity decreased by 15±6%) and a compensatory contraction (25±9% increase) of the upper abdominal wall muscles (upper rectus and external oblique), with no changes in the lower anterior muscles (lower rectus and internal oblique). Patients tolerated lower volume loads (604±310 ml; p=0.030 vs healthy subjects) and developed a paradoxical response, that is, diaphragmatic contraction (14±3% EMG increment; p<0.01 vs healthy subjects) and upper anterior wall relaxation (9±4% inhibition; p<0.01 vs healthy subjects). CONCLUSIONS: In functional dyspepsia, postprandial abdominal distension is produced by an abnormal viscerosomatic response to meal ingestion that alters normal abdominal accommodation.