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.
A unit that can be mounted to a toilet or urinal that has probes to test for vitamins, pH, sugars, salts, blood, etc that tracks each movement. This will provide direct feedback to the users diet and consumption habits. The lagging indicators could be aggregated overtime and read through a laptop, phone, tablet or even sent direct to a watch. It can provide a user the ability to directly correlate their eatting habits with direct data to their bodies. The smart toilet can have multiple users so families could chose their account through a toggle switch prior to using the toilet.
The main unit would be located on the outside of the toilet which would process the readings. Probes that connect from the main processing unit to the toilet have to be manufactured and presumably replace frequently so there has to be careful consideration as to ensure the cost of these replacement probes are affordable.
The first success metric would be to be able to unify all the tests in a single processing unit which could be priced affordablely.
The next success metric would be to locate or develop a probe that is durable yet effective with a high enough sensitivity and accuracy.
The third success metric is to solidify a price point to what consumers would be willing to pay for the Main unit and the respective probes.