ABSTRACT
OBJECTIVE: This work validates a novel non-invasive method to identify periods of cyclic motor activity in the colon using multichannel skin-surface electrical recordings on the lower abdominal region, termed electrocolonography (EColG). METHODS: EColG recordings were made from 21 human subjects during a 3 hr meal-response study. A signal processing pipeline based on Continuous Wavelet Transform time-frequency analysis was used to quantify the spectral power in the colonic frequency band ( ≈ 2-6 cycles per minute; cpm) during the fasted and fed states. RESULTS: EColG identified a substantial 7.4 ± 3.5× maximum transient increase in motor activity in the fed state versus the fasted state, as well as a 38.3 ± 16.7% sustained spectral power increase in the colonic frequency band. The dominant frequency was 3.61 ± 0.49 cpm, with activity localized primarily in the infraumbilical region near the (recto-)sigmoid colon segments. CONCLUSION: The colonic meal-responses identified with EColG were closely concordant with rectosigmoid motor activity previously characterized by intracolonic high-resolution manometry. This study is the first to demonstrate that body surface electrical recordings can properly identify rhythmic colonic activity stimulated by food intake. SIGNIFICANCE: The new EColG technique is inexpensive, portable, and presents the opportunity for reliably measuring colonic motility by noninvasive means. We anticipate that EColG could be applied to monitor the progression of post-operative ileus, and more precisely diagnose abnormal colonic motor patterns in patients suffering from common functional disorders, such as irritable bowel syndrome.
