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167 Water-perfused colonic manometry 7 these were classified as neurogenic because they require a luminal stimulus and/or extrinsic neural input for their generation. The second group consisted of all other propagatingmotor patterns (cyclic, short-single, and long-single motor patterns). 17 Since the cyclic motor pattern consisted of pressure events with a frequency of 2–6 cpm and corresponds to the smooth muscle slow waves, known to be generated by the pacemaker system responsible for the smooth muscle slow waves 30,31 , these motor patterns were classified as myogenic (i.e. there are a initiated within the muscle). These myogenic motor patterns made up 98% of all propagating activity in healthy adults and appear to be under significant extrinsic nerve influence. 17 In this current study, it is this myogenic motor pattern that shows the most striking differences between the patients and healthy adults. Colonic meal response The normal distal colonic increase in propagating cyclic motor patterns observed after a meal in healthy adults 17 was not seen in these children. The rapid increase in their incidence after a meal has been taken as evidence that these myogenic motor patterns are influenced by extrinsic neural inputs. 13 Neurally mediated feeding response of the colon in experimental animals is a well-known phenomenon. 32–34 A lack of increase of this motor pattern after a meal was also observed in adult patients with slow-transit constipation, leading us to speculate that a neuropathy of the extrinsic parasympathetic inputs to the colon may be the cause. This may also be the case in our constipated children. It cannot be excluded that the abnormality lies within the pacemaker system of ICCs because in eight of 18 children, the cyclic propagating motor pattern was absent prior to or after the meal and in all children the recorded pressure events appeared, at times, in a non-propagating and chaotic fashion (Figure 3A). The low number or even absence of the cyclic motor pattern was more notable in constipated children than in constipated adults. While there may be some methodological explanations for this difference (see section on potential limitations below), the question remains as to why this would be the case. While the motor patterns may change with age, an equally plausible explanation is that the neuronal lesions in these constipated children may be more severe. Since the manometry studies have been performed in these children, five of them have had ileostomies fashioned and two have had a subtotal colectomy. Therefore, some of these severely constipated children may be treated surgically long before they would be seen as adult patients. This may also suggest that these children had a preexisting and more serious morbidity than the adults. Of the remaining children, several different therapeutic strategies were used (high dosage of oral laxatives, n = 1; sacral neuromodulation, n = 3; daily transanal colonic irrigation, n = 5; Kleanprep combined with