At some point, constipation — defined as fewer than three bowel movements a week, hard stool or difficulty passing stool — comes for most of us. If you're worried about your constipation, it's best to see a doctor. But if you'd simply like to get things moving, these tips can help.

Start with fibre

Every expert we spoke with said dietary fibre is key. But few of us get the recommended amount: 21g to 38g a day, depending on your sex and age. Ideally you need a mix of soluble and insoluble fibre, said Ethan Balk, clinical associate professor of nutrition at NYU Steinhardt. Think of insoluble fibre as adding bulk, which pushes waste through the colon, and soluble fibre as creating a gel-like consistency that eases its passage. If you're building more fibre into your diet, drink more water, too; it helps the fibre do its job, said Dr Arthur Beyder, a gastroenterologist at Mayo Clinic. Without enough fluid, increasing fibre can actually make constipation worse, so pair every extra serving of fibre with a glass of water.

Five fibre-rich foods that can help

An apple with the skin has nearly five grams of fibre, and it's naturally high in pectin, a soluble fibre that can help regulate bowel movements, Dr Beyder said. Eating the skin is important because that's where much of the fibre is concentrated.

Kiwi is one of Dr Beyder's go-to recommendations. In one study of 200 people, participants who ate two green kiwis a day — without the skin — had "significant and sustained" increases in bowel movements. Kiwi contains both soluble and insoluble fibre, as well as an enzyme called actinidin that may help with digestion.

Prunes and prune juice, classic constipation relievers, "do the trick" for two reasons: fibre and sorbitol, Dr Balk said. Prunes are high in sorbitol, a sugar alcohol that can produce a "laxative effect" by drawing water into the intestinal tract. A small handful of prunes or a glass of prune juice can be effective for many people.

Leafy greens are rich in the insoluble fibre that can speed transit in the gut. Daily kale consumption has been shown to significantly improve bowel movements. Other options include spinach, Swiss chard and collard greens, which can be added to soups, salads or smoothies.

Oatmeal averages four grams of fibre per serving. It contains a soluble fibre called beta-glucan, which can make stool easier to pass and promotes healthy gut bacteria. Choosing plain oats and adding your own fruit or nuts is better than flavoured instant oatmeal, which can be high in added sugar.

Get going with coffee

Coffee often makes you poop — though it's not entirely clear why. It has over 1,000 chemical compounds, and there are "likely multiple mechanisms" for how coffee works, Dr Beyder said. What is known is that coffee often acts quickly, stimulating the colon within four minutes, one study found. And if you are sensitive to caffeine, that same study found that decaffeinated coffee was also effective. So the effect isn't purely about caffeine; other compounds in coffee may also play a role.

Other drinks that can help

Water is the most important drink for relieving and preventing constipation. Staying well hydrated helps keep stool soft and easier to pass. Warm liquids, especially in the morning, can also help stimulate bowel movements. Herbal teas such as peppermint or ginger may soothe the digestive tract, though the evidence is more limited. Prune juice is another classic option, thanks to its sorbitol content. Carbonated water may help some people, but it can also cause bloating, so it's not for everyone.

What to avoid

Alcohol and caffeine in excess can be dehydrating, which can worsen constipation. Highly processed foods, which are often low in fibre and high in fat and sugar, can also slow digestion. If you're increasing fibre, do it gradually to avoid bloating and gas. And don't rely on laxatives regularly without medical advice, as long-term use can cause dependency.

When to see a doctor

If constipation is new, severe, or accompanied by blood in the stool, abdominal pain, vomiting or unexplained weight loss, seek medical attention promptly. Persistent constipation that doesn't respond to dietary changes should also be evaluated by a healthcare professional. For most people, small changes — more fibre, more water, and a little movement — can make a real difference.