Constipation is a common disorder in children, but little is known about its etiology. Rectal impedance planimetry determines segmental rectal cross-sectional area (CSA) and pressure, allowing detailed description of rectal motility. The aim of the present study was to compare rectal motility in healthy and constipated children.
We analyzed data from 10 children (1 girl) with constipation according to the Rome III criteria, mean age 8.8 years (standard deviation ± 1.2), and 10 healthy children (5 girls), mean age 9.9 years (standard deviation ± 1.5). CSA was determined at 3 levels (4, 5.5, and 7 cm from the anal verge). The resting rectal motility was recorded for 30 minutes followed by a distension protocol to assess compliance. Runs of phasic rectal contractions were defined as changes of >10% from baseline CSA and lasting at least 2 minutes. Rectal dimensions were expressed as mean CSA.
A low-amplitude contraction pattern (3%–5% of baseline CSA) with a frequency of 6 to 8/minute was present in all of the children. There was significantly more time with phasic rectal contractions in constipated children (median 38%, range [0–100]) compared with healthy children (median 8.8%, range [0–57]) (P < 0.05). The rectal CSA was higher in constipated children (median 1802 mm2 [range 1106–2948]) compared with healthy children (1375 mm2 [range 437–1861]) (P < 0.05), but compliance did not differ (constipated: median 38 mm2/H2O [range 12–86] vs healthy 33 mm2/H2O [range 10–63]) (P = 30).
In children with constipation, we found phasic rectal contractions for a significantly longer period compared with healthy children, and their rectum is larger than normal.
*Institute of Clinical Medicine, University of Aarhus
†Department of Pediatrics, Aarhus University Hospital, Skejby
‡Neurogastroenterology Unit, Department of Hepatology and Gastroenterology V, Aarhus University, Hospital, Aarhus, Denmark.
Address correspondence and reprint requests to Iben Moeller Joensson, MD, PhD, Department of Pediatrics A, Aarhus University Hospital, Brendstrupgaardsvej 100, Skejby, DK-8200 Aarhus N, Denmark (e-mail: firstname.lastname@example.org).
Received 17 December, 2012
Accepted 24 July, 2013
This study was supported by Toyota Fonden; Fonden af 17-12-1981, Aarhus University, Kong Christian den 10. Fond, Fonden af 1870.
The authors report no conflicts of interest.