Q. I’m a bit embarrassed to ask my doctor about this, but lately I’ve noticed that my stool floats in the toilet. Should I be concerned?

A. Probably not. There are two components of stool—gas and fat—that cause it to hover on the surface of the water in the toilet.

Most commonly, these so-called “floaters” are due to the fourth burrito or second helping of chili from the day before. When gas is the culprit, you also may notice that you pass gas more frequently than normal. The good news is, there is no reason to be alarmed if your stool floats for a day or so.

However, if your stool is consistently very foul-smelling, greasy and floating, there is more reason to be concerned. This usually indicates the presence of fat in the stool, and high levels are never normal. Fat in the stool often reflects an underlying problem in the gastrointestinal tract.

Here’s what happens: The pancreas, liver and gallbladder help the body digest the fat we consume. When these organs become diseased (for example, due to pancreatitis), dietary fat passes through our gastrointestinal tract largely undigested and results in the formation of floating, “oil slick” stools. If this describes your stool, you need to consult a gastroenterologist. To find one near you, check with the American College of Gastroenterology, Patients.GI.org.