http://journals.lww.com/jpgn/Fulltext/1996/10000/Colonic_Transit_Time_in_Constipated_Children__Does.7.aspxColonic Transit Time in Constipated Children: Does Pediatric Slow-Transit Constipation Exist?Benninga, M. A.; Bller, H. A.; Tytgat, G. N. J.*; Akkermans, L. M. A.; Bossuyt, P. M.; Taminiau, J. A. J. M.Free AccessArticle Outline

Author InformationDepartment of Pediatrics;*Department of Gastroenterology;Department of Surgery, University Hospital, Utrecht; and Department of Clinical Epidemiology.Address correspondence and reprint requests to Dr. M. Benninga, Department of Pediatrics, Academical Medical Centre, Meibergdreef 9, 1105 AZ Amsterdam.

AbstractSummary: In adults, slow-transit constipation is a wellestablished form of constipation with abdominal pain and an empty rectum on examination. Marker studies in these patients, mainly women, show a markedly slowed transit time in all colonic segments. No studies in constipated children are available that assess the existence of slowtransit constipation. In a prospective study, a total of 94 referred constipated pediatric patients, 63 boys and 31 girls (median age, 8.0 years), underwent colonic-transittime measurements using radioopaque markers to evaluate the pattern of transit. In addition, orocecal-transittime measurements using the hydrogen breath (lactulose) test, anorectal manometry, and behavior studies using the Child Behavior Checklist were performed in all children. Based on the upper limit (mean + 2 SD) of total colonic transit time (CTT) in constipated children, we arbitrarily separated patients into two groups. Children with CTTs >100 h were said to have pediatric slow-transit constipation (PSTC), while patients with CTTs 20% of markers was still present. Abdominal x-ray films were obtained using a high-kilovoltage fast-film technique to reduce radiation exposure (estimated surface exposure, 0.08 mrad per film).Localization of markers on abdominal films relied on the identification of bony landmarks and gaseous outlines as described by Arhan et al.(10). Markers were counted in the right, left, and rectosigmoid regions, and mean segmental transit times were calculated according to a previously described formula(9,10). The normal range for segmental transit times was based on the upper limits (mean + 2 SD) from a study by Arhan et al. in nonconstipated children(10).Back to Top|Article OutlineOrocecal Transit TimeThe method employed to study OCTT was as described by van der Klei-van Moorsel et al.(11). Studies were performed after a low-fiber diet the day before and an overnight fast. End-expiratory breath samples were taken before ingestion of 10 g of lactulose (20 ml of a 50% solution) and at 15-min intervals thereafter, to a maximum of 240 min(12). At all time points, measurements included two samples taken 1 min apart. The breath was collected in a 60-ml plastic syringe with a side hole and a mouthpiece at the tip opening(11). The H2content of the expelled air was measured by the Hoekloos Lactoscreen(11)and expressed in parts per million (ppm). The OCTT was defined as the period between oral lactulose intake and a rise in hydrogen excretion to 10 ppm above basal values. The test was terminated when this rise in hydrogen excretion was sustained for two subsequent time intervals.H2nonproducers were defined as children with a peak excess breath H2concentration