There are many things that can contribute to constipation. Here are six of them—and what to do about them.

Being constipated is hard—to put it quite literally. And having to deal with the associated symptoms of bloating, abdominal pain and hard stools that are often painful to pass is even worse. But take comfort in knowing that you're not alone. According to the U.S. Department of Health and Human Services, constipation—which is partially defined as pooping fewer than three times a week—affects 16 percent of American adults and doubles as we age. Approximately 33 percent of adults 60 and older deal with chronic constipation.

It's important to know that constipation is not considered a disease, but a symptom of an underlying problem. Changes to your lifestyle, mental health and diet are just some of the reasons you may feel backed up. Here are six possible reasons you can't poop, including tips from registered dietitians on what you need to do to help keep things regular.

poop emoji made of modeling clay

1. You May Be Dehydrated

From plump, elastic skin to increased energy levels, staying hydrated offers numerous benefits to our body's various organs, including the digestive tract. In fact, according to the U.S. National Library of Medicine's resource, MedlinePlus, not drinking enough water every day is one of the key reasons people experience constipation.

"At least a liter of water usually enters our colon during digestion, but only a small portion of that is excreted as part of our stool," says Nashville-based registered dietitian Grace Goodwin Dwyer, M.S., M.A., R.D., L.D.N. "Poop that has had too much water removed from it, either because you're dehydrated or because you're pooping infrequently, is going to be pretty hard."

Daily water intake requirements vary from one person to the next—with activity level and surrounding environment all playing a role in how much you need to drink. So while your recommended daily amount will vary based on these components, the Institute of Medicine of the National Academies does offer general recommendations for staying properly hydrated. For males, that's achieved by consuming approximately 3.7 liters of total water per day (about 15 cups), and females, around 2.7 liters daily (about 11 cups). But your fluid intake doesn't have to come from just plain ol' water. Beverages—including juices, sodas, coffee, milk and tea—and food sources also count towards a person's total water intake. (Psst—here are some of our favorite hydrating foods to help you meet your water goals!)

2. You're Stressed and Feeling Anxious

Everybody experiences stress and anxiety differently. According to the Centers for Disease Control and Prevention (CDC), for some, stress can cause anxiety, fearfulness or feelings of helplessness. Others develop more physical responses, ranging from rapid heartbeat and dizziness to sleeplessness and, you guessed it, constipation.

"Stress can drastically influence our hunger, leading some people to emotionally eat and others to avoid eating," says Kristen Carli, R.D., owner of Camelback Nutrition & Wellness, a private nutrition practice in Scottsdale, Arizona. "It can also greatly influence our gastrointestinal function."

According to 2018 research published in the journal Frontiers in Microbiology, there's a direct link between mental health and gut health. Chronic stress not only affects the gut microbiota but can also lead to the onset of digestive issues such as irregular bowel movements and irritable bowel syndrome (IBS). Stress can also result in the digestive process of peristalsis (wave-like movements that move food through your gut ) abruptly stopping as the body moves from a relaxed state into a fight-or-flight sympathetic nervous response, ultimately being a sneaky reason you can't poop.

Learning what stress management techniques work for you can really help. "It can be as simple as relaxing in a bath with a glass of tea and a good book or more high intensity, like [an indoor cycling] class," explains Carli. "I just guide patients on identifying what self-care activities appeal to them and suggest seeking these behaviors out instead of turning to food to cope with stress."

3. You're Not Eating Enough Fiber

Integral for balancing blood glucose levels, gut health and preventing the onset of chronic diseases, fiber is an essential macronutrient that we often overlook. In fact, if you've been struggling with constipation, Dwyer recommends assessing your daily dietary fiber intake levels. "It's helpful to know what's going on in our bodies, and sometimes boosting a specific type of fiber may help sort out a bowel movement issue."

For healthy adults, the 2020-2025 Dietary Guidelines for Americans recommend a dietary fiber intake of 22 grams to 34 grams per day. Adult males typically require more fiber than females—between 28 grams to 34 grams. But despite the benefits of incorporating more fiber-rich foods into your diet, according to the Dietary Guidelines for Americans, more than 90% of American females and 97% of males fall short of the recommended amount of daily fiber intake, averaging just 14 grams of dietary fiber a day.

"Sometimes people think they need to add a supplement like a powder or drink to increase their fiber intake," explains Carli. "But I recommend starting with fiber from whole food sources because in addition to tasting better, whole food sources also provide additional nutritional benefits like vitamins, minerals, and antioxidants."

And that's not all foods rich in fiber have to offer. Whole grains—like brown rice, nuts, seeds and vegetables—are great sources of insoluble fibers, which Dwyer says help to add bulk to your stool, making them larger and preventing them from hardening. Insoluble fibers also promote a sense of fullness. "Soluble fibers, like those found in oats, beans and chia seeds, help to stabilize blood sugar and can actually lower your blood cholesterol by binding to bile in the GI tract," adds Carli.

4. You've Had a Recent Change in Diet

Although upping your daily fiber intake will most likely be beneficial in the long run, a drastic change in diet can often result in short-term side effects—like constipation—as your gastrointestinal tract takes time to adapt. "If you do not eat much fiber and you suddenly consume lots of fiber, you will likely have some uncomfortable gastrointestinal symptoms, like bloating and gas," explains Carli. "Start with 1/4 cup of legumes per day, for example, for a few weeks before increasing to 1/2 cup per day for a few weeks. Very slow increases will prevent these uncomfortable symptoms."

Processed foods that are high in sodium, as well as high-fat, low-carb diets like the ketogenic diet, are also the culprits for irregular bowel movements. According to 2022 research published in the journal Nutrients, eating too much salt can decrease the amount of water in your poop, making it harder, and more difficult to pass.

"If you're specifically struggling with constipation, I'd incorporate foods that have laxative effects, such as flax seeds, chia seeds, berries and stone fruits—peaches, plums, apricots," adds Dwyer. "Start with 2 tablespoons for the seeds and 1 cup for the fruit per day. And, don't forget that you'll need to also increase your water intake to help your body move this fiber along."

5. You Need to Up Your Exercise Routine

Your level of physical activity may be another reason you can't poop on the regular. In addition to losing muscle strength, decreasing bone density and contributing to poor circulation, a sedentary lifestyle also increases the occurrence of irregular bowel movements, according to the National Library of Medicine's resource MedlinePlus. Results from a 2019 review of the literature published in the Scandinavian Journal of Gastroenterology suggest that exercise may be a practical, effective treatment for constipation.

Exercise might also improve your gut's microbiome. For example, results of a 2019 study published in Nutrients suggest a correlation between an increase in physical activity and the improvement of gut health. For healthy females above the age of 65, daily brisk walks were responsible for increasing intestinal Bacteroides, an essential type of microbiome bacteria.

6. You're on a New Medication or Supplement

Too much of a good thing isn't always a good thing, as is the case with food supplements. While iron and calcium are important nutrients required by the body for blood and skeletal health, having too much can slow down bowel functions, thus leading to constipation.

The same can be said for certain medications. According to a 2018 review of the literature in the journal Medicine, antihistamines, opioids, blood pressure medicines and even antidepressants, can all play a role in the regularity (or lack thereof) of your bowel movements. Some work by slowing down the time it takes for food to pass through the digestive tract, while others draw too much fluid from the GI tract. Both essentially increase the incidence of constipation, a risk that gets higher as we get older.

This is why healthcare providers and dietitians recommend increasing not just your dietary fiber levels, but your daily water intake as well. "I strongly urge people to remember that water is a part of this equation, too," says Dwyer. "Many people who struggle with constipation are dehydrated and find that upping their fluid intake, especially in the morning, can make a world of difference."