One gram of feces contains approximately 1 million to 400 million bacteria.

"Men don't grow, women don't give birth, bones are like sticks, people become deformed, weak, and have abdominal fluid." These are the terrifying symptoms of schistosomiasis. Schistosomiasis, commonly known as the "big belly disease," causes extreme emaciation, ascites, and enlarged spleens. Schistosomiasis not only renders people unable to work but, in severe cases, can even be life-threatening.

The people of Tezi Township, Puge County, deep in the mountains of Liangshan Yi Autonomous Prefecture, Sichuan Province, once suffered such afflictions. With abundant sunshine and rainfall, mild winters and mild summers, the moist earth bred a large number of snails—the hosts of schistosomiasis eggs. Snails are the intermediate hosts of schistosomiasis. "Many people in our village lost their lives to this disease," an elderly resident of Tezi Township recalls with dread. Records of schistosomiasis destroying nine out of ten homes and families in many parts of Sichuan.

"The first step in prevention and control is to mobilize local residents to use the toilets in designated areas," a staff member from the Institute of Parasitic Diseases at the Sichuan Provincial Center for Disease Control and Prevention told reporters. Human and animal feces are one of the main sources of schistosomiasis. Schistosomiasis, a horrific disease, was not fully contained in Puge County, Liangshan Prefecture, until 2015. Fang Lin, head of Tezi Township, told reporters, "The construction of sanitary toilets and biogas digesters has reached a penetration rate of 90% in villages, with a utilization rate of 95%, effectively controlling the source of infection." Zhou Yibiao, a professor at the School of Public Health at Fudan University, believes that the "toilet revolution" has not only improved infrastructure and sanitation but also changed the mindsets of most villagers. "The construction of toilets has helped control the spread of schistosomiasis and intestinal diseases, and has far-reaching consequences." The toilet reform campaign in Liangshan, Sichuan, is a microcosm of China's "toilet revolution."

In the early years of the People's Republic of China, rural areas were generally untidy, with many people and animals living together in many villages. The lack of toilets and pens for livestock was extremely common, making disease control and prevention extremely difficult. Intestinal infectious diseases that seriously impacted public health, such as dysentery and typhoid, were prevalent. Among children, the prevalence of ascariasis is as high as over 70%.

The problem of rural toilet sewage was once widespread in China, stemming from the agricultural civilization's belief that "the success of a farm depends entirely on manure." The toilet culture of the agricultural era made composting and collecting human feces and urine commonplace.