Intestinal Electrical Stimulation: Methodologies, Effects, Mechanisms, and Applications

Although the earliest study of electrical stimulation of the intestine was reported more than 40 years ago, the development of the field is slow compared to cardiac pacing or other areas of neuromodulation, including spinal cord stimulation, deep brain stimulation, and motor cortex stimulation. With electrical stimulation of the gut, an organ of the gut is stimulated and the functions of the organ, in turn, are altered. These altered organ functions may be attributed to either/or the local or peripheral effects of the stimulation or the central neuronal effects of the stimulation. Methodologies of IES include patterns of stimuli, placement of electrodes and delivery time of stimuli. IES is able to pace or entrain intestinal slow waves and normalize intestinal slow wave dysrhythmia. Intestinal contractions can be inhibited with IES of high stimulation energy but may be enhanced with synchronized IES. Intestinal transit may be inhibited or enhanced with IES of appropriate parameters, resulting in an alteration in absorption. The major hindrance in the advancement of IES is similar to that of GES, including the invasive nature of the methodology and the lack of implantable device suitable for IES. The other issue faced is the development of a suitable implantable stimulator.