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181 Solid-state colonic manometry 8 Spectral analysis of colonic pressure wave data Spectral analysis was performed with custom scripts written in Python utilizing the SciPy ecosystem. The amplitudes of the signal for 33 logarithmically-spaced frequencies between 1 every 16 min to 16 per min were obtained by calculating the global wavelet spectrum 22 of the synchrosqueezed 23 continuous wavelet transform using the Morse wavelet. 24 This resulted in a spectrum for preprandial and postprandial periods and for each available region in each subject. Statistical analysis Manometry data are expressed as mean ± SD. The average number, velocity (speed of propagation), extent (distance of propagation), and amplitude of each type of propagating motor were determined. As the data from children in the previous publication were recorded with a different catheter type, with a different sensor interspacing, no attempt was made to statistically compare contraction characteristics between both groups. To describe the postprandial response, dominant frequencies of contractile activity were quantified for 1 hour before and after initiation of the meal. Frequency spectra were analyzed by computing the ratio of the spectrum between the pre- and post-prandial periods and calculating the bootstrap 95% confidence interval (with 100 000 draws) of the mean amplitude of each group’s spectra, repeated for all regions (ascending/transverse, descending and sigmoid colon). Similarity between groups is observed where the confidence intervals overlap. Ethical considerations This study was reviewed and approved by the institutional review board of Nationwide Children’s Hospital (Columbus, Ohio, USA). RESULTS Subject characteristics Data from 19 children with FC were analyzed; the median age was 11.1 years (IQR 7.3- 14.0, range 3.9-19.5) and the sample consisted of 11 boys (58%). The median duration of symptoms was 8.1 years (IQR 6.1-11.1). Table 1 shows patient characteristics, including the diagnostic and therapeutic workup that children had received prior to their colonic manometry.