Effects of colonic electrical stimulation using different individual parameter patterns and stimulation sites on gastrointestinal transit time, defecation, and food intake

This study aimed to compare the effects of colonic electrical stimulation (CES) on gastrointestinal transit time (GITT), energy consumption, stool frequency, stool consistency, and food intake using different individual parameter patterns and stimulation sites. Eight beagle dogs underwent surgery and CES. First, CES was conducted to determine the individual parameters with different pulse configurations, based on symptoms. Second, influences on energy consumption and GITT were compared between CES sessions with different pulse configurations. Third, GITT, stool frequency, stool consistency, and food intake were compared to assess the effects of CES at different stimulation sites. The individual parameters varied greatly among the dogs. In proximal colon electrical stimulation (PCES) and rectosigmoid colon electrical stimulation (RCES), energy consumption was lower with the constant pulse width mode than with the constant pulse amplitude mode (p = 0.012 and p = 0.018, respectively). There was no statistical difference between the two pulse configurations in GITT assessment. The PCES, RCES, and sequential CES sessions significantly accelerated GITT compared to sham stimulation. There was no statistical difference in GITT between PCES, RCES, and sequential CES sessions. Compared to sham CES session, RCES and sequential CES sessions exhibited significant higher stool frequency (p < 0.001 and p = 0.001, respectively), and PCES and RCES sessions inhibited food intake (p = 0.003 and p = 0.002, respectively). Constant pulse width mode is an appropriate pulse configuration for individual CES. At different stimulation sites, CES may exert different effects on stool frequency and food intake. This study provides an experimental basis for the clinical application of CES.