Migrating motor complex after ileal bypass Fig. 4. Representative traces of the migrating motor complexes recorded from the partial bypass for 2 weeks (A, B) and for 4 weeks (C, D). Dotted lines show oral (A, C) or bidirectional (B, D) propagation. duration, interval and AUC of MMCs in each channel are shown in Table 1. Compared to the control, the amplitude was attenuated in every channel (P = 0.000, 0.000, 0.002 at channel 1, 2, 3, respectively). In contrast to the 2-week model, the duration of MMC was increased in channel 2 (P = 0.003), indicating that the duration of the MMCs recov- ered to the control state in the bypassed loop. Similarly, the interval of the MMCs recovered to the control level. Compared to the 2-week model, the amplitude in channel 1 was more attenuated (P = 0.000) but no significant changes were noted in the bypassed loop (channel 2, 3, P = not significant). The mean AUCs showed no significant change between 2- and 4-week model. Aborally-propagat- ing MMCs occurred in 11/25 (44%), orally-propagating MMCs in 8/25 (32%), and bi-directionally propagating MMCs in 6/25 (24%). Compared to the 2-week model, the proportion of orally-propagating or bi-directionally prop- agating MMCs did not change significantly (P = 0.422). (proximal to the anastomosis, oral and anal side of the loop), but the contractions in channel 1 did not propagate to channel 2 (Fig. 5A), and the bypass loop had in- dependent MMCs not coordinated to the proximal segment. In channel 4 (distal to the anastomosis), no defi- nite MMCs could be detected. Twenty MMCs were sam- pled at each recording channel and analyzed. The mean amplitude, duration, interval and AUC of MMCs in each channel are shown in Table 1. Compared to the control, the amplitude was attenuated in channel 1, 2, and 3 (P = 0.002, 0.000, 0.000, respectively) and the duration was shortened in channel 1 (P = 0.044). The mean AUC decreased sig- nificantly at channel 1, 2, and 3 (P = 0.000, 0.000, 0.007, re- spectively). Nineteen of twenty (95%) MMCs propagated aborally, which was similar to the control state, and 1 (5%) simultaneous MMC was observed within the loop. Neither orally-propagating nor bidirectional MMCs were observed. Total bypass for 2 weeks (n = 6) Periodic contractions were observed in channel 1, 2, 3 Total bypass for 4 weeks (n = 5) Periodic contractions were noted only in channel 2 and thesurgery.or.kr 255