After 24-h esophageal MII-pH monitoring, the MII-pH data were downloaded and analyzed using dedicated software (BioView Analysis; Sandhill Scientific Inc.). In this study, the numbers of GER events were counted for 4 h from the start of water infusion at the time of delivery of the half-solid nutrient and from the start of infusion of nutrient at the time of delivery of pectin solution and liquid nutrient. A computerized algorithm (Autoscan; Sandhill Scientific Inc.) was used to identify reflux episodes as changes in impedance progressing in time from the distal to the proximal esophagus. The tracings were subsequently reviewed manually by the investigators to ensure that the automated algorithm correctly identified reflux episodes. Reflux episodes were classified as: (a) liquid-only, if there was only a decrease in impedance progressing distally to proximally; (b) gas-only, if there was only a rise in impedance above 3,000 Ohms in at least two channels progressing distally to proximally; and (c) mixed (gas-liquid or liquid-gas), if there was a combination of the liquid and gas impedance patterns.(13,14) Gas-only reflux episodes were not included in the analysis, and the total number of liquid-only and mixed reflux events was calculated, since liquid-only reflux was observed less frequently than mixed reflux. Reflux episodes were further classified as: (a) acid, if a pH nadir of less than 4.0 was recorded during the MII-detected reflux patterns; (b) weakly acidic, if the nadir pH was between 4.0 and 7.0; and (c) non-acidic, if the nadir pH was above 7.0.(13,14) In addition, any reflux extending as far as the most proximal impedance probe at 17 cm above the LES was also counted. The numbers of each type of reflux event after the two kinds of meals—half-solid and the combination of pectin solution and liquid nutrient—were compared. Data were expressed as mean ± SE. Statistical analysis was performed using the Wilcoxon signed rank test and chi-squared test, and differences at p<0.05 were considered to be statistically significant. This study was approved by the local Ethics Committee of Katoh Hospital, and written informed consent was obtained from the patients or their family members. Results All of the 10 participants completed the study protocol without any adverse events. There was no significant difference in the total number of GER events during 4 h after delivery of the half-solid nutrient and the combination of pectin solution and liquid nutrient (5.7 ± 1.2 vs 5.3 ± 1.0/4 h, p = 0.678). The mean numbers of acid reflux, weakly acidic reflux and non-acidic reflux events after delivery of the half-solid nutrient and liquid nutrient were 3.2 ± 1.1 and 2.4 ± 0.9/4 h (p = 0.345), 1.4 ± 0.7 and 0.8 ± 0.4/4 h (p = 0.075), and 1.1 ± 0.5 and 2.1 ± 0.6/4 h (p = 0.208), respec- tively (Fig. 2). The number of acid reflux events after delivery of the half-solid nutrient tended to be higher than that after delivery of the combination of pectin solution and liquid nutrient. When the total reflux events in the 10 subjects were analyzed by dividing them into acidic (acid and weakly acidic) reflux and non-acidic reflux, acidic reflux was significantly more frequent after delivery of the half-solid nutrient than that after delivery of the combina- tion of pectin solution and liquid nutrient (80.7% vs 60.4%, p = 0.018). The incidence of GER events, extending as far as the most proximal impedance probe, tended to be higher during delivery of the half-solid nutrient than during delivery of the combination of pectin solution and liquid nutrient (47.4% vs 34.0%, p = 0.153). Time course changes in reflux events during the 4 h after meals are shown in Fig. 3. The number of reflux events after delivery of the half-solid nutrient tended to be higher than after delivery of the Fig. 2. Total number of gastroesophageal reflux events during 4 h af- ter the start of feeding. Fig. 3. Time-course of gastroesophageal reflux events after the start of feeding. 192 doi: 10.3164/jcbn.11-58 ©2012 JCBN