Does Dairy Cause Constipation? Here’s What You Need to Know…
If you’ve been struggling with sluggish digestion, bloating, or infrequent bowel movements, dairy might be playing a role. Most people think of dairy as a trigger for diarrhea—but for about 30% of those who are lactose intolerant, it can actually slow digestion, leading to constipation. If your gut feels stuck and nothing seems to be working, dairy could be a hidden culprit.
Let’s unpack why that happens—and what you can do about it.
What Exactly Is Dairy—and Why Can It Be So Tricky for Digestion?
Dairy includes milk, cheese, yogurt, cream, and anything made from the milk of mammals (like cows, goats, or sheep). The main sugar in dairy is called lactose—and here’s where things get interesting…
To digest lactose, your body needs an enzyme called lactase. Babies have plenty of it (since breast milk is full of lactose), but lactase levels tend to drop off with age. When you cannot digest lactose, this means you are lactose intolerant. It may surprise you to learn that up to 70% of adults worldwide are lactose intolerant, with higher rates seen in East Asian, African, Indigenous, and Hispanic populations.
With lactose intolerance, lactose isn’t digested properly, and it ferments in the gut, producing gas (hello bloating). It also draws water into the intestines, which is why many people get loose stools after eating dairy. But for some, it has the opposite effect—slowing digestion and contributing to constipation.
So, if you find yourself bloated, gassy, or irregular after eating cheese or putting cream in your coffee, it might be your body’s way of telling you it doesn’t have the tools to break down lactose anymore.
3 Ways Dairy Can Cause Constipation
1. Lactose Intolerance Can Show Up as Constipation
While lactose intolerance is often associated with diarrhea, research shows up to 30% of those affected experience constipation instead. Why? It’s not well understood, but research suggests it may be due to undigested lactose disrupting the gut microbiome, triggering low-grade inflammation, or slowing motility in the intestines (Source).
Instead of stimulating the bowel and causing loose stools, in some people, lactose actually has a constipating effect—especially when methane-producing gut bacteria are involved (more on that below).
2. Saturated Fat in Dairy Slows Things Down
Dairy products like cheese, butter, and cream are high in saturated fat, which can delay gastric emptying and slow transit time (Source). Additionally, calories from fat often replace calories from carbohydrates associated with dietary fiber. When food moves more slowly through your digestive tract—and you’re not eating much fiber—that’s a recipe for constipation.
3. Your Gut Microbiome May Not Be Loving Dairy
Your gut is home to trillions of bacteria that help regulate digestion, and everyone’s microbiome is a little different—kind of like a fingerprint. Some people have a gut that handles dairy just fine, while others can tolerate small amounts, and some are super sensitive to even the tiniest bit.
Some evidence suggests that dairy can alter the balance of gut microbes in ways that slow down bowel movements. If your gut bacteria don’t vibe with dairy, it can lead to sluggish digestion, bloating, and irregularity. This might explain why your best friend can down a latte with whipped cream and feel totally fine, while your gut throws a tantrum halfway through a scoop of yogurt.
The Methane Link: When Gut Bacteria Make Things Worse
When lactose-intolerant people consume dairy, the undigested lactose gets fermented by gut microbes in the colon, releasing gases like hydrogen, methane, and hydrogen sulfide. One of these—methane—can slow down digestion by interfering with how your intestines contract and move stool along. It increases contractions, but not in a productive way—they’re less coordinated and less effective, leading to slower transit and constipation (Source).
But here’s the kicker: methane doesn’t just show up on its own.
In people with higher levels of a specific group of bacteria called methanogens, the hydrogen gas produced during fermentation (like after consuming dairy) gets converted into methane. Research shows that people with chronic constipation tend to have more methanogens in their gut than people who don’t struggle with it (Source).
So, if you’re lactose intolerant and eating dairy, your body may be producing even more methane than usual—not only from the fermentation process itself, but also from hydrogen being turned into methane. For those with constipation, this can add fuel to the fire by further slowing gut motility.
What You Can Do About It
If you suspect dairy is contributing to your constipation, here’s how to experiment with reducing or modifying your intake:
Step 1: Try Low-Lactose Dairy Options
Not all dairy causes the same reaction. Fermented dairy products contain probiotics and lower lactose levels, which may actually help improve digestion:
Aged cheeses (cheddar, parmesan, Swiss) have very little lactose.
Greek yogurt and kefir contain probiotics that can support gut motility.
Lactose-free milk provides the same taste and nutrients as regular milk without the lactose.
Optional: Try a Digestive Enzyme
If you’re not ready to part ways with your favorite creamy dishes, you can also try using an over-the-counter digestive enzyme like Lactaid, which helps your body break down lactose. This can be especially helpful when you’re eating out or indulging in something you don’t have a substitute for.
📝 Important note: While enzymes can help with lactose digestion, they won’t address other ways dairy can contribute to constipation—like its high saturated fat content or how it affects your gut microbiome. So if symptoms persist, even with enzymes, it’s a sign something deeper may be going on.
Step 2: Cut Out Dairy for 2-4 Weeks
To see if dairy is a problem for you, try eliminating it completely for a few weeks. Keep track of how your digestion changes—do you feel lighter, less bloated, or more regular? If your constipation improves, you might have your answer.
Step 3: Be Smart About Dairy-Free Alternatives
Switching to plant-based alternatives? That’s great! But not all plant-based swaps are gut-friendly. Be careful with:
Coconut-based dairy substitutes, which are also high in saturated fat and can slow digestion. Consume in moderation.
Emulsifiers & thickeners (carrageenan, guar gum, xanthan gum), which may disrupt gut health and cause bloating.
Added sugars, especially in plant-based milks, which can feed gut bacteria in ways that promote bloating and slow motility.
Inulin and chicory root are common “prebiotic” fiber additives often found in plant-based yogurts, protein bars, and coffee creamers. While they can be beneficial in small amounts for some people, they’re highly fermentable and may cause bloating, gas, or discomfort—especially if your gut is already sensitive.
Final Thoughts: Could Dairy Be Behind Your Constipation?
Dairy isn’t the enemy for everyone—but if you’re dealing with bloating, trapped gas, or inconsistent BMs, it’s worth exploring whether or not it’s part of the picture. The good news? You don’t have to swear off every dairy food forever. You just need to find the version—and amount—that works for your gut.
Your body is always giving you signals. Tune in, experiment, and see what helps you feel your best.
