No matter how chill your bowels usually are, constipation happens. And while it may be tempting to reach (okay, lunge) for some OTC relief, your bod may be trying to tell you something—you know, besides that you’re backed up. If you’re wondering why things are slower-moving than normal, here are 13 sneaky culprits and what to do about them:

1. Fiber

Yep, the same thing that helps move things along can also cause a traffic jam in your colon. The biggest faux pas many people make is increasing their fiber intake without also upping their water intake. “It’s a balance of the two that keeps you regular,” says gastroenterologist Niket Sonpal, M.D. Because fiber soaks up water, the lack of H20 can result in poop that spends way too long in the digestive tract—and feels like you’re passing a giant boulder. “Gradually increase your water intake as you increase your fiber,” says Sonpal. “It’s the only way to experience the benefits of proper fiber intake.”

2. Thyroid imbalance

The thyroid regulates a smorgasbord of organs. When your thyroid hormones are out of whack, the entire body goes into slow-mo, including your bowels. “The slower the system, the longer the digestive contents have to be reabsorbed by the colon, resulting not only in decreased frequency of stools, but harder stools,” says Catherine Ngo, M.D., board-certified gastroenterologist at Saddleback Memorial Medical Center in California. Your doc can check for a thyroid deficiency and help your bod get back to its regularly scheduled programming.

3. Traveling

Travel-related constipation is super common, and stems from the disruption in your normal routine—number two or otherwise. “Dealing with travel-related constipation isn’t that different from what you’d do about it when you’re at home,” says Sonpal. Simply increase your fiber and water intake, and try keeping your exercise and rest routines as status quo as possible.

4. White rice

“White rice is refined and stripped of all the good stuff like fiber, proteins, calcium, magnesium, and potassium,” says registered dietician Deborah Malkoff-Cohen. Basically, some of the very nutrients that can help you poop. The indigestible fibers that remain can obstruct the bowel and lead to constipation. “Opt for brown rice instead, which is nutritionally superior and contains enough fiber to avoid that ‘backed-up’ feeling,” she adds.

Related: 18 Things You Should Never Put In Your Vagina

5. Antidepressants

Constipation can be a side effect of certain SSRI antidepressants, such as Prozac (fluoxetine), though it’s more of a problem with older tricyclic antidepressants (TCA), such as Elavil (amitriptyline), says Sonpal. “Simply put, TCA are known for pulling water out of your colon, thus causing harder and more difficult stool passage,” he explains. If you think this is why you’re feeling backed up, check in with your doc about using a gentle stool softener or adding more fiber and water to your diet.

6. Bad bathroom habits

Some people hold it to avoid the grossness of public bathrooms, while others delay pooping because they’re in the middle of something. But if you put off boarding the number two train too often, your body’s natural sensors (the ones that tell you it’s toilet time) can go haywire. “You eventually confuse the muscles in the rectum and anal sphincter and develop constipation,” says Gina Sam, M.D., assistant professor of gastroenterology at Mount Sinai Hospital in New York City. Plus, the longer the poop sits there, the more water your colon absorbs out of it, making it super hard to pass when you finally do sit on the throne.

7. Low potassium

“Potassium is an important electrolyte for proper muscle movement,” says Sam. When your potassium is low, the muscles in your colon don’t move as much and can lead to constipation. Luckily, the cure is simple: Add more potassium to your diet with foods like potatoes, bananas, mangoes, prunes, raisins, and kiwis. Bam.

8. Pregnancy

When there’s a bun in the oven, the hormonal changes shift your digestive tract into relaxation mode, which in turn reduces contraction frequency of the colon, says Ngo. And as the pregnancy progresses, the pressure the growing baby puts on your bowels makes it more difficult to unclog your pipes. Use a combination of hydration, exercise, fiber supplements, and stool softeners to keep things moving—and if necessary, pregnancy-compatible osmotic laxatives, suggests Ngo.

9. Dairy

“Full-fat dairy can cause constipation due to its high fat/low fiber content,” says Malkoff-Cohen. Fat can slow digestion, while a sensitivity to lactose (milk sugar) can present as diarrhea or constipation. Either cut down on your dairy intake, or balance the scales by mixing more foods into your diet that contain fiber.

Related: 8 Sneaky Ways To Debloat In Just One Day

10. Irritable bowel syndrome

If you have IBS with constipation, or IBS-C, your bod isn’t pushing food from your stomach to your poop shoot as quickly as it should be. That, combined with your colon not secreting enough water, can lead to hard, dry stools, says Sam. (Le ouch.) It’s not known what causes IBS-C, but luckily there are many treatments available—including medications, special diets, cognitive behavioral therapy, and meditation.

11. Calcium supplements

“Calcium supplements can have a mild binding effect in the stool, making it difficult to pass,” says Sonpal. “Too much calcium in your blood can also change the way your muscles receive the signal to contract your colon, and could make these muscles sluggish.” Calcium carbonate supplements have a bad rap for this, so you may want to switch to calcium citrate. But really, the best way to score calcium with the least risk of constipation is to get it from foods like low-fat dairy and fortified OJ, says Sonpal.

12. Finicky pelvic muscles

Our pelvic floor and sphincter muscles are the dynamic duo that helps us poop when the time is right. But when these muscles don’t relax properly—or contract instead of relax—the colon basically holds your poop hostage so it can’t pass through easily. “There are numerous causes for pelvic floor muscles to dysfunction,” says Sonpal. “It’s best to see your physician so they can arrange for proper testing.”

13. Too many laxatives

Laxatives stimulate bowel activity, but relying on them too much can lead to more constipation. Over time, the nerve cells that release the necessary chemicals for your colon to do its thing end up depleted. This leads to your bod needing higher and higher doses of laxatives to do the trick—until eventually, they don’t work at all. “More of a problem is that when they stop working, the other simple measures that we might try have less chance of working as well because those stimulatory neurons are now dead,” says gastroenterologist Pradeep Kumar, M.D, who suggests ditching the laxatives for a fiber supplement and/or Miralax, which is safe for long-term use.

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