The colour of your stool can indicate a number of things related to your body. It can indicate a type of disease that you are suffering from or certain food or medications that you have been taking.
Black stools that are odourless and non-sticky indicate that you have been consuming iron tablets or medicines that contain bismuth, such as bismuth subsalicylate.
Also Read: Foods That Cause Dark Stools
Black, tarry, foul-smelling and sticky stools indicate that there is a bleeding in the stomach from an ulcer or a gastritis or there is a bleeding in the intestines. The colour change occurs as a result of the chemical reaction between the blood and the digestive enzymes in the intestine.
Red or maroon stools indicate that the bleeding is taking place in the lower parts of the intestine. This is because there is less time available for the blood to react with the enzymes in this case. Sometimes the red colour is also caused when you consume food items like beetroot or any red-coloured vegetable, cranberries or red food dyes.
Grey or clay-coloured stools indicate that there is very less or no bile in the stool. This is an indication of biliary obstruction, where the flow of bile to the intestine is blocked either by a tumour or gallstones.
Yellow-coloured stools indicate the presence of fat that has not been digested. This happens as a result of diseases like chronic pancreatitis, cystic fibrosis, pancreatic cancer or celiac disease. In this case, the pancreas stops functioning properly. The stool appears yellowish in colour, is greasy and has a foul smell due to the presence of high fat that has not been properly digested.
Green stools can be a result of the inclusion of certain green foods in your diet like green vegetables and foods that contain purple or green dyes. It can also occur when you have diarrhoea, and the stool is forced to pass through the intestines and there is very little time for the bilirubin to go through the usual chemical changes.