Let’s talk about poop. Sure, it’s not exactly dinner-party material, but it’s important to learn all you can about bowel movements — what’s weird, what’s normal, what’s healthy, what’s not.

That’s because your poop (stool) is an important clue to your overall digestion and health.

Your poop can reveal serious signs of infections, digestive problems, and even early signs of cancer, according to Anish Sheth, MD, a gastroenterologist at Penn Medicine Princeton Health in Plainsboro, New Jersey, and the coauthor of the books What’s Your Poo Telling You? and What’s My Pee Telling Me?

Take a look at these facts about poop, and then pay attention to how often you go, how long it takes, and what the result looks and, yes, smells like. Simply put: Know your poop.

1. What Is Poop Made Of?

Water makes up about 75 percent of your stool, research has shown. The rest is an often-stinky combination of fiber, dead and live bacteria, other cells, and mucus. Soluble fiber found in foods like beans and nuts is broken down during digestion and forms a gel-like substance that becomes part of your poop.

On the other hand, foods packed with insoluble fiber, such as corn, oat bran, and carrots, are more difficult for your body to digest, which, per the Mayo Clinic, explains why they may emerge in your poop (stool) looking relatively unchanged.

2. Color Matters When It Comes to Poop

As you may have seen in pictures of poop, the color can vary — a lot — depending on what kinds of food you’ve ingested and other factors. Dr. Sheth has seen patients get full work-ups for bright red stool that turned out to be related to nothing more than the passage of beets.

But don’t ignore red stool, as it may be rectal bleeding, a potential symptom of a serious health issue that needs treatment, per the Cleveland Clinic.

Leafy vegetables can cause green stool, while certain medications can make your poop look white or clay-colored. Look out for jet-black stool. Though it could be from something as harmless as iron supplements or black licorice, the color could be a sign of bleeding or tumors in the upper gastrointestinal tract, Penn Medicine notes.

3. So Does the Shape

Did you know there’s an actual diagnostic chart that classifies human poop into seven categories based on shape and consistency?

The Bristol Stool Form Scale identifies seven types of poop:

Type 1: Separate hard lumps, like pebbles, that are difficult to pass
Type 2: Hard and lumpy, resembling a sausage
Type 3: Sausage-shaped with cracks on the surface
Type 4: Thinner, more snake-like that is smooth and soft
Type 5: Soft blobs with clear edges
Type 6: Mushy pieces with ragged edges
Type 7: Liquid with no solid pieces

Types 3 and 4 are considered normal, and the shapes are signs of a healthy diet and lifestyle, reports the Cleveland Clinic. Types 1 and 2 signal constipation, while types 6 and 7 are diarrhea and can be signs of an infection, food poisoning, or a gastrointestinal illness. If your poop consistently falls on this part of the scale, talk to your doctor to determine the underlying cause. Type 5 typically indicates a lack of fiber in the diet, which lends bulk to stool and acts as a glue to keep the poop stuck together as it exits your body.

4. Terrible-Smelling Poop May Be a Sign of Infection

It’s no news that poop never smells pleasant, but particularly pungent stool is often a sign of infection, according to Sheth. Terrible-smelling poop is a signature side effect of a stomach bug caused by Giardia parasites, ingested most often during swims in untreated water in springs, rivers, or lakes, according to the Centers for Disease Control and Prevention (CDC). It could also suggest a more serious digestive condition such as ulcerative colitis, Crohn's disease, or celiac disease, according to Mount Sinai.

5. Consistency Is Key When It Comes to Bowel Movements

Do you hit the bathroom at the same exact time every morning, or can you go days before you need to poop? It’s all normal, says Sheth — the important thing is that you’re consistent with your own routine. Generally, anywhere from three bowel movements per day to three a week falls into the normal range, according to the Mayo Clinic.

A big decrease in poop could be due to a diet change, which is why many people find they’re less regular on weekends or on vacation — they may be eating less fiber or working out less often, both of which promote healthy digestion. Other factors affecting poop output — either a decrease or an increase — are gastrointestinal disorders, an underactive thyroid, or colon cancer, according to the Cleveland Clinic.

Cultural differences play a role, too. Sheth notes in his book that South Asians unload nearly three times as much stool as British people do, a difference he explains that’s largely due to the higher fiber content in the average Indian diet.

According to Sheth, on his website DrStool.com, the average American man excretes 150 grams (g) (about one-third of a pound) of poop every day, or the equivalent of five tons in a lifetime!

6. How to Tell if It’s Diarrhea or Constipation

Digestion can take anywhere from 24 to 72 hours, during which time the food you’ve eaten travels down your esophagus to your stomach, then to your small intestine, your large intestine, and out through the anus.

Diarrhea is the result of your poop passing too quickly through the large intestine, where most of the water content is absorbed. Constipation, on the other hand, is when it takes too long for stool to pass through. Loose stools can be due to many factors, including stomach viruses, foodborne illness, food allergies or intolerances, like lactose intolerance, or from other digestive issues, according to the National Institute of Diabetes and Digestive and Kidney Diseases.

Constipation, on the other hand, is when it's difficult to pass a bowel movement or you poop less frequently than normal. Constipation is the most common gastrointestinal complaint, according to Johns Hopkins Medicine. Certain medications, lack of exercise, and a lack of fiber or liquid in the diet are all common causes of constipation.

7. Healthy Poop Should Sink in the Toilet

Listen for the sound of your poop as it hits the water in the toilet. Floating stools are often an indication of high fat content, which can be a sign of malabsorption, a condition in which you can't absorb enough fat and other nutrients from the food you’re ingesting, reports Mount Sinai. It can also be a sign of celiac disease or chronic pancreatitis.

8. It’s Normal to Pass Gas 10 to 18 Times a Day

Incidents of flatulence are embarrassing, at least for some, but farting is completely healthy and the result of harmless bacteria breaking down food in the large intestine. Your colon is filled with bacteria that release gas as a by-product of digesting the food you eat. Your body absorbs some of it into the bloodstream, which you breathe out through your lungs, and expels the rest out of your other end. It’s normal to pass gas anywhere from 10 to 18 times a day, according to the American College of Gastroenterology.

9. Stool Transplants Can Treat Certain Infections

Fecal microbiota transplants are real — and they work. Research shows a fecal transplant — in which stool from a healthy person is placed in the colon of an infected person — is an effective treatment for C. difficile bacterial infection.

The trillions of good bacteria in a healthy person’s poop can recolonize another person's digestive tract and treat infections that haven’t responded well to other treatments, including antibiotics and probiotics, Sheth says.

Researchers are looking into the potential for fecal transplants to treat other illnesses, including inflammatory bowel disease (IBD), autism, and obesity, but the procedure is currently not approved for these conditions.

So how do you ask someone to be your poop donor? And more importantly — who? Sheth suggests asking someone whose healthy gut bacteria likely differs from yours; ideally, a friend or family member who lives in a different household.

10. Watch How Long Your Spend on the Toilet

Sitting too long on the toilet can contribute to hemorrhoids, or swollen blood vessels in and around the anus. The longer you stay in the bathroom trying to poop, the more pressure and stress you put on your backside. Sitting for too long on the toilet can also restrict blood flow around the anal area, which can make hemorrhoids worse.

Most of the time, a diet devoid of fiber, which keeps your bowels regular and prevents constipation and hard poop is to blame. Most Americans eat 10 to 15 grams of fiber a day, according to Harvard Health Publishing, but the USDA recommends 25 grams for women and 38 grams for men.

11. Your Cell Phone Might Be Covered With Poop

Wash your hands well after using the bathroom, or poop may travel with you. British researchers discovered that one in six cellphones were contaminated with poop (stool), which can spread E. coli bacteria, after they collected nearly 400 samples in 12 different cities.

Since phones tend to travel with us everywhere — especially places where we eat, like kitchen counters, restaurant tables, and desks, to name a few — the E. coli bacteria detected on them may play a role in spreading illness.