Solid gastric emptying scintigraphy in children with rumination syndrome

Introduction: Rumination syndrome is a functional gastrointestinal disorder characterized by postprandial effortless regurgitation of food which is re-chewed and then re-swallowed or spat out. Its prevalence in children has progressively increased over time and has been described to be up to 5.1% in children between 10 and 16 years old. The underlying pathophysiological mechanisms of rumination syndrome are still not entirely elucidated. It is known that an increase in pressure gradient across the lower esophageal sphincter because of subconscious abdominal and intercostal muscle straining leads to episodes of retrograde flow of gastric content from stomach to esophagus and mouth. Clinically the patients present with effortless regurgitation which reflects the underlying pathophysiology. Limited data are available on the role of gastric emptying in children with rumination. The aim of this study was to describe the pattern of gastric emptying of a solid meal in children with rumination syndrome.

Methods: We prospectively recorded the data of solid meal gastric emptying scintigraphy in children with a diagnosis of rumination syndrome. Medical records were searched for demographics, clinical and manometric features. Diagnosis of rumination syndrome was made clinically according to Roma IV criteria and confirmed on esophageal high resolution impedance manometry. Solid meal gastric emptying scintigraphy was performed as recommended by the Society of Nuclear Medicine and Molecular Imaging and the American Neurogastroenterology and Motility Society. A solid test feed based on cooked eggs on toast or melted cheese on toast or on pasta (as in Drubach L et al. 2010), radiolabelled with 10 MBq of [^99mTc]Tc-nanocolloid, was ingested in approximately 10 minutes. All drugs with known effects on gastrointestinal motility were stopped at least 72 hours prior to the study. Gastric emptying was assessed as the percentage of radioactivity retained in the stomach over 4 hours using the geometric mean of the decay-corrected anterior and posterior counts for each time point. Anterior and posterior gamma camera images were obtained 0, 1, 2, 3 and 4 hours after the test meal ingestion. A gastric retention of >10% at 4 h was considered as evidence of delayed gastric emptying.

Results: Thirty children (13 males; median age 13.8 years, range 5.6-16.4) with rumination syndrome underwent gastric emptying scintigraphy with a solid test feed. Fifteen children (50%) had evidence of delayed gastric emptying with a median gastric retention of radiolabelled feed at 4 h of 25% (range 12-50%), significantly higher than the group with normal gastric emptying (median 2%, range 0-8%; p<0.00001). No difference in age (median 13.6 years, range 5.6-16.2 vs median 13.9 years, range 9.5-16.4; p=0.5) and disease duration (median 38 months, range 3-80 vs median 25, range 1-146; p=0.3) was found between the two groups. Symptoms and type of rumination were similar between children with delayed and normal gastric emptying. The number of rumination episodes in the group with delayed gastric emptying was higher than in the group with normal gastric emptying (median 3.5, range 1-10 vs median 6.5, range 2-36; p=0.2), but did not reach statistically significance difference.

Conclusions: Delayed gastric emptying was noted in half of children with rumination, suggesting its potential role in the pathogenesis of paediatric rumination in a significant subgroup of patients. Patients with delayed gastric emptying experienced more episodes of rumination. This feature requires further investigation to clarify the role of delayed gastric emptying in the development of rumination syndrome. Moreover, our results might also advocate the need for additional pharmacological agents and/or dietary modifications for a successful management of the disease. Further larger multicentre cohort studies are required to confirm these findings.