Utility of Monitoring Fasting Phase During Pediatric Colonic Manometry Studies

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.

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

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.

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