Utility of Monitoring Fasting Phase During Pediatric Colonic Manometry Studies.

Introduction: Colonic manometry (CM) is a diagnostic procedure used to evaluate pediatric patients with refractory constipation, fecal incontinence, Hirschsprung disease, and pediatric intestinal pseudo-obstruction. Pan-colonic high-amplitude propagated contractions (HAPCs), measured by CM, reflect an intact neuromuscular function of the colon. Current guidelines recommend starting CM with fasting recording for 1-2 h, but no prior evaluation has determined the diagnostic yield of the fasting phase. We aimed to determine the utility of the fasting phase during CM studies.

Methods: We evaluated CM studies conducted at a tertiary pediatric center (2018-2022). Fasting phases of normal CM studies were evaluated.

Key results: In 433 included studies 241 (55.7%) females, median age (9.7 years), the average fasting recording lasted 126 min. A total of 193 (44.6%) studies exhibited fasting HAPCs, with 123 (28.4%) being pan-colonic. The presence of pan-colonic HAPCs was based solely on the fasting phase in 11 (2.5%) studies. Patients with fasting pan-colonic HAPCs were younger (median age of 6.9 vs. 9.8 years, p = 0.0001) and had a higher rate of postprandial HAPCs (69.1% vs. 25.2%, p < 0.0001). Most fasting pan-colonic HAPCs presented during the first 60 min (94/123, 76.4%). All studies demonstrated HAPCs after stimulation with bisacodyl. In analyzing just the initial 30 min of fasting on CM, only 2 (0.5%) studies would have been misclassified as abnormal, with no bisacodyl administration in these studies.

Conclusions & inferences: Shortening the fasting phase minimally affects next-day CM results and could reduce patient inconvenience, hospital-related costs, and potential side effects.