Motor patterns, intraluminal pressures, volume capacity, and histoanatomic characteristics were studied in full thickness specimens from ileal reservoirs (orthotopic ileal bladders) removed during corrective surgery. Contractile activity was recorded in situ before corrective surgery. Morphological examination was performed with both light and electron microscopy. Two populations of interstitial cells of Cajal (ICC) were identified: ICC at the level of the deep muscular plexus (ICC-DMP) and ICC at the level of the myenteric plexus (ICC-MP). The ileal reservoirs left as tubes generated phasic activity when filled with liquid, and all retained the ICC-MP; however, after extended periods (e.g., 8 yr), these reservoirs lost the ICC-DMP and were less responsive to distension. The detubularized ileal reservoirs were not responsive to distension and did not generate phasic activity; none had ICC-DMP and all had a disrupted ICC-MP network. In conclusion, motor patterns were found to be specific for each type of reservoir, and the two populations of ICC had characteristics specific for the type of bladder reconstruction.