Temporal changes in occurrence frequency of bowel sounds both in fasting state and after eating

Food evaluation technology that takes into account the constitutional predisposition and health of an individual's digestive system should aid in the development of value-added foods for patients and people who require health care. Based on the assumption that the degree of bowel activity changes depending on each individual's constitutional predisposition, health, and tolerance of the consumed foods, we investigated bowel sounds as an index of bowel activity. We have developed a method for investigating changes in bowel activity by performing long-term continuous recording of bowel sounds and observing changes in the occurrence frequency of bowel sounds per unit of time. In order to obtain basic data, we made recordings of eight healthy adults. We observed that bowel sounds continued even after the most recently consumed food had been nearly completely digested. In addition, we found that the occurrence frequency of bowel sounds of normal intensity (stethoscope audible) did not synchronize with that of minimal intensity (amplifier audible) in the fasting state. In contrast, the former did synchronize with the latter during digestion.