The shelf made it easier for people to inspect stool for signs such as blood, parasites, unusual colors, or other changes. Before modern medical testing became widely available, these observations could provide useful clues about health.
As plumbing and hygiene standards improved, toilet designs gradually changed. Newer models became more popular because they reduced odors, were easier to clean, and removed waste more quickly.
Although shelf toilets are less common today, they can still be found in some older European homes and buildings. What may seem strange to travelers today was once a practical design shaped by the medical knowledge and needs of its time.