What makes faeces brown

What comes out is a clue to what goes on inside, and knowledge is a terrible thing to waste. Consider this your school on stool. In a typical bowel movement, roughly three-quarters of stool volume is water. The remaining 25 percent is a mixture of bacteria live and dead , undigested food such as seeds, nuts, corn and beans and substances contributed by the intestines and liver, such as mucus and bile, which aids in the digestion of fats.

The scale was devised after Stephen Lewis and Ken Heaton noticed in a study that an unexpected prevalence of defecation disorders were related to the shape and type of stool. They published their new scale in in the Scandinavian Journal of Gastroenterology. The Bristol scale categorizes stool by seven types:. In their initial studies, Lewis and Heaton found that types 1 and 2 were more prevalent in females, while types 5 and 6 were more prevalent in males.

Red blood cells are much smaller than most of the other cells in the human body — about seven microns across. A micron is one millionth of a metre. For comparison, a human hair is about 70 microns across. Red blood cells make up about one quarter of the trillion cells in your body — but they don't make up one quarter of your weight, because they are so small.

Each red blood cell carries about million haemoglobin molecules. Between all of them, they carry 2. I'll talk about the 'globin' part first, just to get it out of the way. There are four 'globin' molecules in each haemoglobin molecule. And yes, they are kind of globular. Each 'globin' is quite big, and is made from various amino acids. Now for the 'haem' part, which ends up making poo brown and urine yellow. Haem is quite a small molecule — about times smaller than a globin molecule.

Right in the middle is a single atom of iron. Getting back to the red blood cells — they are very flexible. They have to be, because on each circuit of the body, they have to squeeze through capillaries that are about 20 per cent smaller than the red blood cells themselves.

The red blood cells get old after about to days. They get more stiff, and find it more difficult to squeeze through the capillaries. Then they get recycled in the spleen. Have you ever wondered just what the spleen does? Well, it does immune system stuff, it stores spare blood for use in an emergency, and it also breaks down red blood cells.

Though bile is naturally green, its pigments change color to yellow and brown as they travel through your digestive system and are broken down by enzymes. If your excrement is brown and solid , you have no obvious reason for concern. It is usually attributed to something you ate, adds Nandi. Eating lots of green, leafy vegetables like spinach or kale — rich in the pigment chlorophyll — will easily give your feces an emerald hue.

Whitish, clay-colored poop is caused by a lack of bile, which can stem from a blockage of bile ducts. Gallstones are one possible culprit of such an obstruction, says Dr. But if you see white poop without any of the aforementioned symptoms, you can wait to see a doctor, Swaminath says. Yellow poop is another potential indicator of bile shortage, which, again, may be related to obstructed bile ducts. It can also mean that the pancreas is not secreting enough enzymes needed for digestion.

When people prep for a colonoscopy , their stool becomes diluted and can also turn yellow, says Nandi. Yellow poop can also arise from excess fat in stool , often due to an inability to break down foods, such as gluten for someone living with celiac disease.

If you think this may be causing yellow stool, you should consult your doctor.