Disturbances in the colon and intestinal microbiota can lead to the development of various chronic non-communicable diseases, often initiated by an increase in tissue permeability. These alterations affect the passive electrical properties of the tissue, making bioimpedance a potential alternative for detecting colorectal diseases. In this study, we present the results of measuring the four components of bioimpedance (real, imaginary, magnitude, and phase) in the rectal tissue of 20 patients undergoing total colonoscopy. The objective was to assess the electrical behavior of the tissue and its relationship with colonoscopy findings, based on the concept of the carcinogenic field effect. The results revealed a statistically significant decrease in impedance magnitude in the presence of disease. Furthermore, the readings exhibited two dispersions, which may be associated with the layered structure of the tissue.