How Long Do Lactose Intolerance Symptoms Last?

If you’re lactose intolerant and have consumed any dairy product intentionally or unintentionally, then you must be searching the internet wondering how long do lactose intolerance symptoms last.
We understand your concern. Knowing when the bothersome symptoms are going to subside would give you some relief. If not, then at least it would help you prepare yourself for dealing with the symptoms for the said time.
So, in this blog, we’re going to talk about everything you need to know about lactose intolerance symptoms and how long they last.
You might be surprised to know that you’re not alone; in fact, lactose intolerance is a very common digestive disorder. It affects nearly 68% of the world’s population, 36% of whom are Americans.
By adulthood, almost 70% of people aren’t able to digest lactose in dairy products due to a decline in the production of lactase.
This causes digestive discomfort in the form of symptoms such as bloating, gas, diarrhea, etc. These symptoms often show up within 30 minutes to 2 hours of consuming dairy. But how long they can exactly last? Let’s find out together…
What Are the Signs & Symptoms of Lactose Intolerance?
Lactose intolerance is a condition in which our body isn’t able to digest the sugar in milk, called lactose. This is because the body lacks an enzyme called lactase, which is responsible for breaking down the milk sugar, lactose.
When an individual does not produce enough lactase to properly metabolize lactose, this causes gastrointestinal distress. This further causes common digestive symptoms, such as:
- Gas
- Nausea
- Diarrhea
- Bloating
- Vomiting
- Abdominal pain
- Stomach cramps
- Growling or rumbling sounds in the stomach
If the symptoms are severe, such as the ones listed below, then there is a possibility that you might have a milk allergy. Food allergies are different from food intolerances. Allergies cause more serious symptoms as they involve the immune system.
- Anaphylaxis
- Throat swelling
- Rash and eczema
- Shortness of breath
- Tingling sensation around the mouth
Food allergies aren’t as harmless as food intolerance, thus it’s important to seek medical attention.
How Long Do the Signs and Symptoms Last?
To determine the duration of lactose intolerance symptoms, you must first find out “how long does lactose stay in your system?”

Firstly, it’s important to note that the severity of symptoms depends on factors such as the amount of lactose consumed and the amount of lactase produced by the body. The more lactose you consume and the less lactase in your body, the more severe the symptoms, and vice versa.
The onset of the symptoms commonly occurs within 30 minutes to 2 hours of consuming milk products. The duration of the symptoms, on the other hand, may be affected by the aforementioned factors.
As a result, for some people, the symptoms may go away within a few hours, whereas for others, they may last longer. Overall, the symptoms only last for as long as lactose remains in your system.
Thus, if you ask, “How long does lactose intolerance diarrhea last?” Then the answer is- “for as long as the lactose stays in your systems.” Even at the most, this couldn’t be more than 48 hours.
Therefore, we can say that the unpleasant symptoms take at most 48 hours to resolve, if not earlier.
Note: If the symptoms of lactose intolerance persist even after 48 hours or become severe, you must seek immediate medical help.
How Long Do the Symptoms of Other Food Intolerances Last?
Here are some other food intolerances and digestive problems that cause similar symptoms. Here is how long their symptoms last:
- Dairy allergy: The onset of the symptoms of dairy allergy occurs within 2 hours of ingestion. If the milk is continued to be consumed then the symptoms could last up to 72 hours.
- IBS: The symptoms of irritable bowel syndrome (IBS) could last a few days or even months.
- Gluten intolerance: The symptoms of gluten intolerance may last up to a few days.
- Alcohol intolerance: The symptoms of alcohol intolerance appear within 20 minutes of consuming alcohol and last up to a few days. The symptoms of alcohol intolerance disappear as soon as alcohol leaves the system.
How to Help Lactose Intolerance Pain
If you wonder, “How to relieve gas pain from lactose intolerance?” Then avoiding dairy is the best way to manage lactose intolerance pain or symptoms.
By avoiding the cause of the problem, which is dairy in the case of lactose intolerance, you can alleviate the unpleasant symptoms.
If you keep consuming foods that contain lactose, then the pain or other symptoms will keep bothering you. Therefore, it’s important to restrict high-lactose foods like milk, cheese, and ice cream. Lactose in heavy cream, yogurt, and aged hard cheese is relatively low.
Some people can tolerate a small amount of dairy without experiencing any symptoms. This is often equivalent to 12–15 grams of lactose (0.4–0.5 ounces) when spread throughout the day. Apart from this, fermented milk products like yogurt and cheese are also often tolerated well by many.
In addition to restricting or avoiding products containing lactose, here are a few other things you can do to ease the pain.

Take over-the-counter medication:
- If symptoms like gas and bloating are bothering you then you can take over-the-counter medication for the same. Taking antacids can help you eliminate stomach cramps and gas.
- For nausea, you can opt for antiemetics. But if you have an aspirin allergy avoid taking antiemetics
Lactase enzyme supplement:
You can even take lactase pills before consuming dairy products in order to prevent symptoms from appearing.
Lactose-free alternatives:
In place of dairy products containing lactose, go for dairy-free and vegan alternatives. Dairy substitutes such as almond milk, rice milk, coconut milk, and soy milk are good for fulfilling the nutritional requirements of the body to some extent.
You might further need to add other food sources as these vegan alternatives often don’t have the same nutritional profile as cow’s dairy.
Probiotic supplements:
Another good way to deal with lactose intolerance related pain or other issues is by taking probiotic supplements. You can also eat probiotic foods such as yogurt, sourdough bread, kimchi, kefir, pickles, kombucha, and sauerkraut.
Probiotic supplements and foods contain good bacteria and enzymes that aid digestion.
Related: Here is the best lactose free yogurt.
Generally Asked Questions Relating To Lactose Intolerance Symptoms
How Long to Get Dairy Out of System?
On a dairy-eliminating diet, it would take up to 2-3 weeks to flush out dairy completely from your system. You would have to avoid all dairy products such as milk (from cows, goats, and buffalo), cow’s yogurt, cheese, etc.
This will require keeping a check on any hidden dairy ingredients as well.
Dairy substitutes such as soy milk, coconut milk, almond milk, and rice milk should be consumed during this period.
On the other hand, if you’re asking about lactose that you might have consumed unintentionally, then it may require 1-2 days to pass through your system.
Unless you keep consuming lactose-containing foods, the lactose you previously consumed will be flushed out of your system within about 48 hours at most.
How Long After Eating Dairy Do Symptoms Start?
The symptoms of lactose intolerance start appearing within 30 minutes to 2 hours of consuming dairy. These symptoms may include gas, nausea, diarrhea, vomiting, bloating, constipation, stomach cramps, etc. Once the undigested lactose passes through the system completely, the symptoms subside.

What Does Lactose Intolerance Poop Look Like?
In approximately 30% of people, lactose intolerance causes constipation. Constipation causes hard or large stools and infrequent bowel movements, along with abdominal pain. It’s also characterized by fecal incontinence and painful defecation.
In others, lactose intolerance causes diarrhea, which is characterized by loose, watery stools and frequent bowel movements.
As lactose intolerance impacts different people differently, lactose intolerance poop couldn’t be distinguished. Also, lactose intolerance generally doesn’t affect the color of the stool.
Which Dairy Goods Have the Lowest Lactose Content?
The dairy goods that have the lowest lactose content are:
- Butter
- Kefir
- Sherbet
- Yogurt
- Sour cream
- Hard cheese
Related: Can lactose intolerant eat chocolate
Conclusion
In conclusion, the symptoms of lactose intolerance are harmless and can’t last more than 48 hours. However, if you’re lactose intolerant, we don’t need to tell you how bothersome and embarrassing these symptoms could be.
Thus, it’s better to make the required dietary changes in order to manage these unpleasant symptoms. As we mentioned earlier, an eliminating diet is the best way to deal with food intolerances like lactose.
But, a dairy-restricting diet could make it difficult for you to get the recommended amount of calcium. Thus, it’s important to incorporate other sources of calcium in your diet such as spinach, kale, tofu, broccoli, etc.
Overall, eat healthy, substitute dairy products with lactose-free alternatives, exercise daily, and make probiotics a part of your routine. All this will help you deal with lactose intolerance in the best way possible.
Lastly, if you’re looking for a probiotic that keeps your gut healthy and alleviates lactose intolerance symptoms, then look no further. Here is our Optima Healthy Gut Solution, which is specially formulated to support better digestive and overall health.