Poop Facts
Why do dogs (and other animals) eat poop?Many animals eat poop on a regular basis. These include rabbits, rodents, gorillas, many insects such as dung beetles and flies, and yes, dogs. |
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Why does poop stink?Poop stinks as a result of the products of bacterial action. Bacteria produce smelly, sulfur-rich organic compounds such as indole, skatole, and mercaptans, and the inorganic gas hydrogen sulfide. These are the same compounds that give farts their odor. |
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Why does some poop float?Floaters are turds that have an unusually high gas content. Sometimes the gases produced by bacteria in our gut don't have a chance to collect into a large fart bubble, but remain dispersed in the feces. The poop then comes out foamy, and has a lower density than water. |
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Why does some poop hurt when it comes out?Turds can get very large and dry if a person is constipated, causing painful stretching of the anal opening. Pooping can also hurt if the person has hemorrhoids. Hemorrhoids are engorged veins in the anal area. A doctor once described them to me as "varicose veins of the anus," which suggests that the valves in the veins that are supposed to keep the blood flowing in the right direction have gotten messed up. Pooping can also be painful if the person suffers from an anal fissure, a tear in the tissue of the rectum. |
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Why is bird poop white?Unlike mammals, birds don't urinate. |
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Why is poop brown?The color comes mainly from bilirubin, a pigment that arises from the breakdown of red blood cells in the liver and bone marrow. The actual metabolic pathway of bilirubin and its byproducts in the body is very complicated, so we will simply say that a lot of it ends up in the intestine, where it is further modified by bacterial action. But the color itself comes from iron. Iron in hemoglobin in red blood cells gives blood its red color, and iron in the waste product bilirubin gives rise to its brown color. |
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