Bowel movements are direct indicators to a persons overall health. There is a saying "you are what you eat." If you consume too many vitamins which are water soluable, they will be excreted through urine. Another example is if you consume too much salt it will also be excreted through urine. There are many things that can be determined through bowel movements. These lagging indicators could be measure and tracked over time to determine any deficiencies, excesses or risks to health based on the data collected. There currently is no way to track your movements except to go to the doctor and request lab work.