For starters, everybody poops, and there's no "right" way to do it, says Larry Good, MD, a board-certified gastroenterologist affiliated with Concierge Choice Physicians. "Each of us poops differently," and some people always tend to have BMs that are kind of watery—and that might be fine, he says. The key is to pay attention to what's normal for you. (Boosting your health and losing weight doesn’t have to be so hard—sign up to get FREE tips delivered straight to your inbox with Prevention’s daily newsletter!)

What GI docs really care about is when patterns change. So if your stool is suddenly much looser than it used to be—and it doesn't get better within a few days—it's time to talk to your doctor. The National Institute of Diabetes and Digestive and Kidney Diseases suggests that adults who've had diarrhea for more than 2 days seek medical help; if you have a fever or notice blood or pus in your stool, you probably ought to phone your physician even sooner. (And keep an eye on those kidneys—check out these 6 signs your kidneys are failing.)

What's causing your new digestive discomfort? Good says the possibilities are vast: It could be a viral or bacterial infection, a side effect of a medication you're taking (like an antibiotic), a recently-developed food intolerance or allergy, or a chronic condition like irritable bowel syndrome. If your bowel issues are accompanied by weight loss, anemia, or severe pain, consider it a red flag that something more serious, like colon cancer, could be to blame. (Here are 7 things your poop says about you.)

Related: I Worked Out 6 Times A Week But My Body Never Changed Until I Made This Simple Change

When you see a doctor, he will likely ask you to describe how severe your loose stools are, says Good. "There is actually a scale, the Bristol Stool Scale, that is used in scientific studies to quantify the severity of diarrhea." Level 1 is constipated, level 7 is super watery, and levels 4 and 5 are normal. Meanwhile, the consistency of your BMs isn't the only change worth tracking: If you're going more or less often than you used to, that's important to discuss with your doc, too. (Let’s talk urine! Here are 7 things the color of your pee says about your health.)

This article originally appeared on Prevention.com.