I did in-depth research about directly and indirectly related apps on the market, to help patients keep track of their data related to bowel movement. Here are some take-aways. Most of those apps did a really good job of designing an easy-to-navigate user interface and provided consistent information for users to keep track of their symptoms and lifestyle data. However, none of them work with a digital-first vision or run an insightful correlation analysis. The datasets are usually inputted manually and lack analysis. These apps address the issue superficially but lack actionable insights. There are also some companies dealing with this issue at a micro level, such as Viome and Seed, as well as a lot of concept design projects like Backtoyou and E. chromi. However, dealing with the issue on a micro-level is very costly and lacks consistency. You can have a sample exam at a lab once, but it is almost impossible for patients to do it on a daily basis. 

Take GoPoop and Cara as examples; I found that both of them have easy-to-use and user-friendly logging interfaces. GoPoop has a calendar view about all the bowel movements, which is more like a diary logging style and has an overview of a specific log entry if a certain day is chosen. It includes the color, type, time stamp, and duration of that stool. However, the visual aesthetic is very close to the real images, which is not comfortable to look at and not fun to use. Cara does a great job of using a color-coded system and beautiful illustrations to visualize the data input. However, it lacks data analysis, and the correlation diagrams are poorly designed without enough support and documentation. We come to the conclusion that it is well-designed but lacks consideration about usability and effectiveness.