Birds do it, bees do it, maybe you’re doing it right now. Bowel movements may not be a popular topic during happy hour, but, to quote a childhood favorite book, “everybody poops” — and everybody occasionally (or more than occasionally) makes a weird poop. But what’s normal, and when should you worry? Here’s what you should keep in mind when you’re trying to figure sh*t out:

1. Looks matter when it comes to poop. Maybe you shouldn’t judge a book by it’s cover, but when it comes to bowel movements, appearances can actually tell us a lot. Start by getting a good idea of what a normal bowel movement looks like by using the Bristol stool chart, a medical aid that was developed to classify stools into seven categories, two of which are ideal. If you want to skip the visual guide at the moment, here’s the lowdown in a nutshell: bowel movements should generally be sausage- or snake-like, either smooth or with minor cracks on the surface. Sausage-like but lumpy stool, hard, nut-like stools, and blobby, fluffy, or liquid stools all indicate possible health problems.

2. Once a day is average — but the jury’s out on what’s normal. “Three times a day to every three days” is an oft-quoted rule-of-thumb among many gastroenterologists, but while it may be catchy, it’s also highly debated. “Going every three days has not really been associated with ‘normal’ in my experience,” Dr. Monya De says. Dr. Westin Childs agrees: “You should be having one bowel movement each and every day that is not difficult to pass or leaves you feeling like you aren’t ‘satisfied,’” he says. “It is not normal to have a bowel movement every other day, or every four days as some people suggest. These are early indicators that you have some sort of gut imbalance that needs to be addressed.” Your bowels, your decision — if you’ve been happily pooping once every three days for years and have no complaints, you’ll find plenty of experts who’ll tell you that’s totally fine. But if you’re dealing with health issues and want to make sure your gastrointestinal tract isn’t the culprit, you may want to push for answers beyond “what’s normal for you is normal.”

3. Yes, poop smells, but the fumes shouldn’t knock you out. No, it’s never going to come out smelling like Chanel No. 5, but if you start having bowel movements that chase you out of the bathroom before your pants are even zipped up, you might want to make an appointment with your doctor. Stool that’s unusually foul-smelling could be a sign of malabsorption of nutrients, which can be caused by anything from lactose intolerance to celiac disease.

4. Diarrhea during your period is normal. Annoying, but normal, anthropologist Kathryn Clancy explains. First off, prostaglandins, the chemical signals that cause your uterus to contract, can sometimes meander over to your bowels, signaling them to do the same — which is why some women end up with more frequent bowel movement or diarrhea during their periods. Progesterone levels also decline right before your period, and since that hormone is naturally somewhat constipating, the sudden drop can have you running for the bathroom.

5. Your medications may be wreaking havoc — and not just the prescription ones. If you’re suddenly experiencing constipation or diarrhea, a new medication may be to blame (opiates are known for the former and antibiotics for the latter). But don’t forget about over-the-counter meds — some of which you may be taking for way longer than the usual round of antibiotics. “Many over-the-counter medications can cause changes in your microbiome which can increase your risk of developing conditions like small bacterial overgrowth, nutrient deficiencies, gut infections like C. Diff colitis, and even osteoporosis,” says Dr. Childs. “The two most common medications include any acid blocker (proton pump inhibitors or H2 blockers) and non-steroidal anti-inflammatory medications like ibuprofen and Tylenol.” Be especially wary of acid blockers — they decrease your body’s ability to digest and absorb nutrients, which changes the composition of bacteria in your gastrointestinal tract, he explains. “These medications aren’t intended to be used for more than 10-14 days at any given time, and many patients have been on them for years,” says Dr. Childs.

6. A change in stool color could be a sign of trouble — but don’t panic
Anything outside of the healthy light-to-dark-brown range can be alarming, but remember that it’s not just illness that can cause stool color changes. The food you eat and the medications you take can do wonky things to your bowel movements, too, so start there before you worry (for example, beets can sometimes explain red stools and Pepto-Bismol can turn your poop black). Still, better safe than sorry, Dr. De says. “I think more than one bowel movement that is frankly abnormal should have you paying very close attention.” And that goes for anything, not just color changes — if something’s not looking right in your toilet bowl and you’re worried, don’t hesitate to make a doctor’s appointment. “Most of the time, if someone is worried enough to come to the doctor, there’s really something there that I can fix,” Dr. De adds.

7. Consistently abnormal isn’t normal
Don’t settle for “my stomach is always wonky!” A shruggie emoticon is no way to treat your body. “Bowel movements can be the canary in the coal mine for everything from hormonal problems to infection to inflammation to cancer,” Dr. De says. The gastrointestinal tract holds the majority of our immune system and a large portion of our neurotransmitters, adds Dr. Childs. “Changes in bacterial concentrations in the GI tract due to stress, diet, lack of exercise impact these systems and can manifest in a variety of ways [like] depression, anxiety, skin conditions, and obesity,” he says. Dr. Childs’ rule of thumb: If your bowel movements are consistently abnormal, meaning three to four days per week on average, that would indicate something is abnormal in your gastrointestinal tract. One to two changes in your bowel movements per week is a warning sign to look into the issue with your doctor. “It’s far better to prevent than it is to treat and reverse,” he says.

There you have it — the lowdown on ensuring that your number twos are #1 (sorry, had to). If you haven’t had enough poop talk, make sure you check out this book.

Diana Vilibert is a freelance writer and copywriter living in Brooklyn, NY. She loves flea markets, martinis, to-do lists, traveling, and wearing leggings as pants. You can see more of her writing at www.dianavilibert.com and follow her on Twitter at @dianavilibert.