Prolonged colonic manometry in children with defecatory disorders.

OBJECTIVES: Colonic manometry is a test used in the evaluation of children with defecation disorders unresponsive to conventional treatment. The most commonly reported protocol in pediatrics consists of a study that lasts approximately 4 hours. Given the wide physiological variations in colonic motility throughout the day, longer observation may detect clinically relevant information. The aim of the present study was to compare prolonged colonic manometry studies in children referred for colonic manometry with the more traditional short water-perfused technology. METHODS: Colonic manometry studies of 19 children (8 boys, mean age 9.4 ± 0.9, range 3.9-16.3) with severe defecation disorders were analyzed. First, a "standard test" was performed with at least 1-hour fasting, 1-hour postprandial, and 1-hour postbisacodyl provocation recording. Afterwards, recordings continued until the next day. RESULTS: In 2 of the 19 children, prolonged recording gave us extra information. In 1 patient with functional nonretentive fecal incontinence who demonstrated no abnormalities in the short recording, 2 long clusters of high-amplitude contractions were noted in the prolonged study, possibly contributing to the fecal incontinence. In another patient evaluated after failing use of antegrade enemas through a cecostomy, short recordings showed colonic activity only in the most proximal part of the colon, whereas the prolonged study showed normal motility over a larger portion of the colon. CONCLUSIONS: Prolonged colonic measurement provides more information regarding colonic motor function and allows detection of motor events missed by the standard shorter manometry study.

Solid-state vs water-perfused catheters to measure colonic high-amplitude propagating contractions.

BACKGROUND: Solid-state (SS) manometry catheters with portable data loggers offer many potential advantages over traditional water-perfused (WP) systems, such as prolonged recordings in a more physiologic ambulatory setting and the lack of risk for water overload. The use of SS catheters has not been evaluated in comparison with perfused catheters in children. This study aims to compare data provided by SS and WP catheters in children undergoing colonic manometry studies. METHODS: A SS catheter and a WP catheter were taped together such that their corresponding sensors were at the same location. Simultaneous recordings were obtained using the SS and WP catheters (both 8 channels, 10 cm apart) in 15 children with severe defecation disorders referred for colonic manometry. Signals were recorded for a minimum of 1 h during fasting, 1 h after ingestion of a meal, and 1 h after the administration of bisacodyl. Solid-state signals from the data logger were analyzed against the perfused signals. All high-amplitude propagated contractions (HAPCs), the most recognizable and interpreted colonic motor event, were evaluated for spatial and temporal features including their durations, amplitudes, and propagation velocities. KEY RESULTS: A total of 107 HAPCs were detected with SS and 91 with WP catheters. All WP-HAPC were also observed with SS. Linear regression analysis showed that SS catheters tended to give higher readings in the presence of amplitudes <102 mmHg and lower reading with amplitudes >102 mmHg. An opposite trend was found for the duration of contractions. No significant difference was found for HAPC velocity. CONCLUSIONS & INFERENCES: SS catheters are more sensitive in recording HAPCs in children with defecation disorders compared with the more traditional WP assembly. There is a difference in measurements of amplitude between the two systems. Solid-state catheters offer potential advantages over WP catheters in children, being portable, safer to use, and may provide data over a more prolonged period.

Interrelationship between colonic muscularis mucosae activity and changes in transmucosal potential difference.

This in vitro study investigated the relationship between rabbit colonic muscularis mucosae motor activity and changes in transmucosal potential difference. Spontaneous muscle contractions and potential difference oscillations occurred independently and were not neurally driven. ACh and histamine directly stimulated the muscularis mucosae, but their mucosal effects were largely indirect, suggesting that muscularis mucosae contractions promote epithelial secretion. 1,1-Dimethyl-4-phenyl-piperazinium iodide and vasoactive intestinal polypeptide induced large potential difference changes but small muscularis mucosae contractions, demonstrating mucosal secretion without significant muscle activity. Lowered intraluminal pH directly stimulated the muscle, whereas a bile salt-lipid mixture evoked TTX- and atropine-sensitive increases in its contractile activity. Increased intraluminal pressure and hypertonic luminal perfusion did not elicit muscularis mucosae excitation. Thus under basal conditions muscle and mucosal activities are independent, but evoked muscularis mucosae contractions can stimulate epithelial secretion. In response to specific luminal stimuli, muscularis mucosae motor activity is increased via the activation of cholinergic nerves. These data suggest that muscularis mucosae and mucosal functions are physiologically linked and that their activities can be coordinated by multiple mechanisms.