Lactose intolerance and IBS share many symptoms, making them easy to confuse. It is possible for both conditions to coexist, and they may even affect each other. Managing them involves dietary adjustments, stress management, and lifestyle changes.
What are lactose intolerance and IBS?
Before we take a look at possible connections, similarities, and differences between these two conditions, we must first answer the question: What even are lactose intolerance and IBS? Because while most people have probably heard these terms before, not many really know what's actually behind them.
Let's start with lactose intolerance. Most people know that those suffering from lactose intolerance don't consume dairy because it makes them feel unwell. But what's happening in the body? Let's take a closer look! Lactose intolerance is a digestive condition that occurs when the body produces insufficient amounts of lactase, the enzyme responsible for breaking down lactose, the sugar found in milk and dairy products. When lactose isn't properly digested, it passes into the colon, where it is fermented by gut bacteria, producing gas and drawing water into the intestine. This can lead to uncomfortable symptoms such as bloating, abdominal cramps, diarrhea, and more. Lactose intolerance can develop at any age, though it is more common in adults, and its severity varies from person to person. While it isn't dangerous, it can significantly impact daily life by influencing dietary choices and social situations. Even going out for a coffee with friends can turn into a challenge.
IBS (irritable bowel syndrome), on the other hand, is a broader functional gastrointestinal disorder characterized by recurring abdominal pain or discomfort. Unlike lactose intolerance, it isn't caused by a single enzyme deficiency. Its exact cause remains unknown, but it is believed to involve a combination of gut-brain axis dysfunction, intestinal hypersensitivity, and motility disturbances. IBS can affect quality of life by making meal planning and social activities more challenging due to unpredictable symptoms.
As you can see, both lactose intolerance and IBS can present with digestive symptoms. However, there are many important differences between the two conditions.
How are lactose intolerance and IBS connected?
Lactose intolerance and IBS (irritable bowel syndrome) are two separate conditions with different causes. However, they do often occur together. So even though they are not at all the same and have different origins, there appears to be some sort of connection between them. How is that possible? And what kind of connection are we talking about here? Let's get into it!
What we already know is that both lactose intolerance and IBS can lead to symptoms like bloating, gas, or cramping, which is part of why they're frequently mistaken for one another. But if you are thinking, "I just need to find out which one it is and adjust my diet", unfortunately, we have to disappoint you: it is not that straightforward, and it is possible to have both conditions at once.
Several studies suggest that people with IBS report lactose intolerance more often than people without IBS. In a meta-analysis comparing IBS patients to healthy controls, IBS sufferers were significantly more likely to report lactose intolerance symptoms and also showed a higher rate of objective lactose intolerance on testing.² This doesn't necessarily mean that one condition causes the other, but it indicates a notable connection: having IBS may make someone more sensitive to lactose or more likely to perceive lactose intolerance symptoms.
Additionally, research shows that many individuals initially diagnosed with irritable bowel syndrome actually have undiagnosed lactose intolerance. In one study, 44% of patients with IBS tested positive for lactose intolerance using hydrogen breath testing.³ This highlights how frequently the two conditions can coexist.
Because the symptom overlap is so strong, it is often recommended to check for lactose intolerance when evaluating IBS-like symptoms, especially if they worsen after dairy consumption.
Shared IBS and lactose intolerance symptoms
On top of often occurring together, lactose intolerance and IBS share a surprisingly large set of symptoms. Both can cause bloating, abdominal pain, gas, and changes in bowel habits like diarrhea or loose stool after certain foods. Not only are the symptoms of the two conditions similar, but they can also affect each other. For example, the discomfort caused by lactose intolerance can cause stress, which may trigger or worsen IBS symptoms in some individuals.
This overlap and connection can make it difficult to identify which condition is responsible for specific symptoms, especially when reactions occur after eating meals that contain multiple potential triggers. This is why careful observation of symptom patterns, food triggers, and timing is so important. Understanding these shared symptoms is a crucial first step toward identifying the true cause of digestive discomfort and choosing the most effective treatment option.
How they can affect each other
Lactose intolerance and IBS don't directly cause one another, but they can influence how strongly symptoms are felt. If someone with irritable bowel syndrome also has lactose intolerance, consuming lactose can lead to more intense bloating, cramps, and discomfort because the digestive system is already sensitive. Likewise, frequent digestive discomfort caused by lactose intolerance may increase stress or anxiety around eating, which is a known trigger for IBS symptoms.
Because of this connection, it is important to find out whether you are suffering from both conditions at the same time and manage them accordingly. Dietary changes that help with your lactose intolerance symptoms won't necessarily improve your IBS symptoms and vice versa. That's why understanding both conditions and how they interact is so important.
How to find out whether you have lactose intolerance and/or IBS
Because lactose intolerance and IBS share many symptoms, finding out which condition you're dealing with—or whether both are involved—usually takes a few steps. The first and most important thing is paying attention to patterns. If symptoms like gas, bloating, or diarrhea consistently appear after consuming dairy products, but not when eating meals that are dairy-free, lactose intolerance may be the cause. If symptoms occur more unpredictably, are linked to stress, or appear after many different foods, it could be IBS.
The next step should always be medical testing. There are several approaches to lactose intolerance testing. Often a hydrogen breath test is used, which measures how well your body digests lactose. This test can provide clear answers without requiring long-term dietary restrictions. IBS, on the other hand, does not have a single diagnostic test. Instead, doctors diagnose it by reviewing symptoms and your medical history and ruling out other conditions.
Because both conditions can coexist, a structured approach—combining symptom tracking, targeted testing, and professional guidance—is very important. Getting clarity helps avoid unnecessary food restrictions and makes it easier to manage symptoms effectively.
Treatment options for lactose intolerance and IBS
Managing these conditions often starts with lifestyle and dietary changes. Following an IBS and lactose intolerance diet can help reduce symptoms like bloating, cramping, and irregular bowel movements. Many people benefit from limiting certain foods, managing stress, staying active, and drinking enough fluids. Medications may also be prescribed to regulate bowel habits or reduce pain, depending on individual needs.
When it comes to treating lactose intolerance, the focus is on managing lactose malabsorption. Avoiding or reducing lactose-containing foods can help, but strict avoidance can make meal planning extremely difficult—especially if you don't want to give up creamy cappuccinos, cheesy pizzas, and delicious ice cream. The use of lactase enzyme supplements, such as the tablets and capsules from LactoJoy, is a great alternative for everybody who doesn't want to live with restrictions. They provide your body with the enzyme it's lacking, which helps it break down lactose more efficiently. By doing that, they allow you to enjoy dairy without discomfort again.
Combining strategies for both conditions is often the most effective way to manage symptoms. And one more very important thing to know: whether you are suffering from lactose intolerance, irritable bowel syndrome, or both—you are not alone. Both conditions are fairly common and, if diagnosed correctly, absolutely manageable.
