A method of data collection of stool data via a mobile device operable to enable monitoring of gastrointestinal function. A related method of long-term monitoring of patient gastrointestinal function, using one or more signal processing tools (e.g. machine learning algorithms) for automatically interpreting patient stool data, including real-time patient-assessments, in order to detect an adverse clinical event from patient stool data. A system for facilitating real-time monitoring the gastrointestinal function, the system comprising: a camera on a mobile device, a user interface that facilitates self-monitoring of stool characteristics, so as to create health-monitoring data; mobile device storage, server storage, and remote storage (with at least one communication link between them) for storing some or all of the health-monitoring data; and a processor for interpreting such health-monitoring data for clinical or other health-monitoring application.