Can't Poop? Here's Everything You Should Know About Constipation

To understand why constipation happens, it helps to know how poop is made. From start to flush, it takes 24 to 72 hours.

1. The food you eat enters your stomach, where it's ground into small particles.

2. The particles head to the small intestine, where enzymes break down fats and proteins so that they—along with other nutrients—can be absorbed.

3. What's left (a liquid mix of fiber, bacteria, undigested fats and mucus from your digestive tract) moves to the large intestine, which pulls out water, making a more solid stool.

4. The stool passes into the rectum, at the end of your large intestine, where it becomes compacted.

5. Once your rectum reaches capacity, your brain gets a signal that it's time to go. When you're ready to push, the abdominal and rectal muscles tense while the sphincter muscles relax.

Sometimes there's a mechanical reason why you're clogged up, says Gina Sam, MD, director of the Mount Sinai Gastrointestinal Motility Center in New York City. For example, the muscles inside your intestines may have trouble moving waste at a normal rate. The longer stool sits, the more water your large intestine absorbs, and the harder and drier (and more difficult to push out) the stool gets. Or there could be an issue with your rectal or sphincter muscles.

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Other conditions that can cause clogs: diseases that affect the nerves, like multiple sclerosis or Parkinson's; rectal issues like fissures (small tears) or hemorrhoids; irritable bowel syndrome; and cancerous growths, which can block your bowels. But in the case of a short bout of constipation, the culprit is often much simpler.

"The neurotransmitters that the brain releases when we're stressed also interact with receptors in the colon wall," says Roshini Rajapaksa, MD, Health's contributing medical editor and a gastroenterologist at NYU-Langone Medical Center. Ongoing anxiety can cause the muscles in your colon to become sluggish, she says.

RELATED: 25 Surprising Ways Stress Affects Your Health

"Maybe your diet isn't as healthy, or you're not drinking as much water as usual," says Dr. Rajapaksa. "You might be sitting still in a car or a plane instead of moving around." Changing time zones can also disrupt your bowel habits. Or you just might not feel comfortable "going" in a different environment.

If you suspect that a medication is to blame, talk to your doctor about what you can do to offset this side effect (altering your diet, for example), or ask if there's another drug that might work better for you.

Any fluctuations in hormone levels—due to your period, pregnancy or perimenopause—can have an effect on your bowels. "Many women who are premenstrual report episodes of constipation, and then they develop looser movements when they get their period," says Dr. Sam. Health conditions that impact your hormones, like thyroid disease or diabetes, can also lead to constipation.

RELATED: 10 Things That Mess With Your Period

Get things moving again may seem like a daunting task if you've been plugged up for a while, but it doesn't have to be. Ditch the following foods and bad habits to bring back your happy gut.

Fiber can't be fully broken down by your digestive system, so it passes relatively quickly through your gut—keeping the rest of your food moving, too. Some of the best sources of fiber are fruits and vegetables, whole grains, legumes and nuts. Adult women need at least 25 grams a day, says Dr. Sam, but most Americans get only about 15 grams.

RELATED: 20 Best Foods for Fiber

You need plenty of fluids to flush waste out of your body and to hydrate your stools so they stay soft.

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"Regularly relying on over-the-counter laxatives can mask the real cause of your constipation, whether it's a poor diet, a medication side effect or even a serious health issue," says Dr. Rajapaksa. Repeated use can also destroy the balance of healthy bacteria in your gut, adds Dr. Sheth.

The muscles in your gut follow the rest of your body's lead. The more you move during the day, the more often those muscles contract, too, propelling waste through your digestive system.

Delaying bowel movements can lead to a cycle of constipation, says Dr. Sheth. "Over the long term, it can actually slow down the functioning of your bowel."

These "good" bacteria contribute to healthy gut flora and thereby improve digestion. One 2014 study suggested that taking probiotic supplements could help increase BM frequency and soften stools.

RELATED: 14 Best and Worst Foods For Digestion

"Even if you're not straining, sitting there for a long time puts increased pressure on your rectum," which can weaken muscles, notes Dr. Sheth. If it takes long enough that you need to bring your smartphone, that's not a great sign. Pushing out a poop should be a reasonably quick, effortless process—no pain is your gain.

RELATED: 13 Surprising Causes of Constipation

Take a look in the toilet (come on, you know you've done it!) and give your poop a quick check-up.

What's normal:

Any shade of brown.

What's not: Red or black, which can indicate blood—though black stools may also be caused by Pepto Bismol, and red can sometimes occur if you eat lots of beets, notes Gina Sam, MD. Whitish or yellow stools could be signs that your body isn't absorbing enough nutrients from food.

What's normal:

Soft and smooth enough to pass easily, but still compact.

What's not: Small, hard rabbit pellets mean you're probably not getting enough fiber. A mushy or liquidy consistency is a sign of inflammation, which could be caused by certain medications, a food intolerance or allergy or an infection.

Watch the video: 3 Ways to Get More Fiber

What's normal:

Some odor. "The gases result from the breakdown of the foods you eat, so a smell is unavoidable," says Dr. Sam.

What's not: A super-intense foul odor. "Most of the time, a very strong smell is due to a high-fat, high-sugar diet," says Dr. Sam, although it could also signal an infection.

What's normal:

One long sausage shape.

What's not: Persistently thin, pencil-like stools—especially if they become skinnier over time—can indicate cancerous growths inside your colon, says Roshini Rajapaksa, MD.