A plurality of colour sensing sections are attached to a toilet seat so as to test a health state or a fecal occult blood portion every time by capturing the feces surface colour during defecation. Before feces which have been excreted from a body sink into a water-seal portion, the circumference of the feces is optically captured to detect the colour of the surface of the feces. By monitoring changes in colour, the health state of the defecator is monitored. In particular, by checking the presence/absence of an occult blood portion, the present invention assists in early detection of colorectal cancer and allows a fecal occult blood test to be performed in a hygienic manner without burdening the user.
