National Poop Day

Facts About National Poop Day

Every day, something most people never think about quietly shapes human health, farming, energy, and even city planning. From the microbes living inside us to the way waste has powered fields and fueled homes, poop has played a surprisingly important role in human history and science. These facts explore how what we flush away connects to the body, the environment, and the way societies have managed resources for centuries.

• Bacteria Make Up Much of What Humans Flush Away

  Human stool is mostly water, but the solid portion comprises a large share of bacteria rather than leftover food. Medical and microbiology references estimate that roughly one-third to one-half of the dry weight of feces consists of bacterial biomass, including both living microbes and dead cells shed from the gut microbiota. 

• Traditional “Night Soil” Once Fed Entire Farming Systems

  For centuries in East Asia, cities collected human feces—known as “night soil”—and sold it to farmers as fertilizer, creating a tightly closed nutrient cycle between urban toilets and rural fields. Historical and agricultural studies describe elaborate collection routes around cities such as Tokyo and in parts of China, where night soil was a valuable commodity before synthetic fertilizers became widespread. 

• Dung as a Major Cooking Fuel for Millions of People

  In many rural regions with scarce firewood, dried animal dung is still shaped into cakes and burned as a primary household fuel for cooking and heating. International energy and health reports note that households in parts of South Asia and sub‑Saharan Africa rely heavily on dung, which provides essential energy but also contributes to indoor air pollution and respiratory disease when burned in poorly ventilated spaces. 

• Biogas Turns Manure and Sewage Into Renewable Energy

  Animal manure and human sewage can be fed into anaerobic digesters to produce biogas—a mixture rich in methane that can generate electricity, heat, or cooking fuel. The United Nations and technical reviews describe thousands of small digesters across China, India, and Nepal, as well as large municipal plants in Europe and North America, turning fecal waste streams into energy while reducing methane emissions from open lagoons. 

• Fecal Microbiota Transplantation Uses Poop as Medicine

  Fecal microbiota transplantation (FMT) takes processed stool from a rigorously screened healthy donor and introduces it into a patient’s gut to reset their microbiome. Clinical reviews show that FMT is highly effective for treating recurrent Clostridioides difficile infection that does not respond to antibiotics, and the U.S. Food and Drug Administration has cleared stool‑derived microbiota therapies for this purpose while research continues into other potential uses. 

• Stool Tests Help Catch Colon Cancer Early

  Modern colorectal cancer screening often starts not with a scope but with stool. Noninvasive tests, such as fecal immunochemical tests (FIT) and stool DNA tests, look for hidden blood or genetic changes shed from tumors or advanced polyps; guidelines from major medical organizations endorse these as effective screening options, with colonoscopy reserved for follow‑up when results are positive.

• Unsafe Poop Disposal Drives Deadly Diarrheal Disease

  When human feces are not safely contained and treated, pathogens can contaminate drinking water, food, and soil, fueling outbreaks of diarrheal diseases such as cholera. WHO and UNICEF estimate that billions of people still lack safely managed sanitation services, and inadequate handling of excreta remains a major contributor to preventable child deaths from diarrhea worldwide.