The color, consistency, and smell of stools say a lot about your health, and, of course, your diet. According to the National Institutes of Health, healthy stools typically sink. However, floating stools do not necessarily mean that there is a problem. Usually, floating stools result from nutrient malabsorption that can lead to gas in your colon and stool, which makes the stool less dense and thus allows it to float.
Malabsorption happens when the body does not completely digest and absorb nutrients from the gastrointestinal (GI) tract. Normal bacteria in the digestive tract help digest foods (typically sugars) that have not already been digested in the small intestine. These bacteria may produce excess gas. When higher amounts of food are digested by bacteria in the lower intestine gas is produced. The gas needs to find a way out by either farting or floating stools.
Having diarrhea and floating stools for more than two weeks may be a sign of nutrient malabsorption. Alternative explanations for floating stools include a change in diet, diarrhea, acute GI infections, and digestive diseases such as celiac disease.