If you experience diarrhea every time after you drink milk, there is probably an underlying condition. Lactose intolerance and milk allergy may be the culprits. Often confused as the same thing, they are quite different and both can cause diarrhea after consuming milk.

Why Do You Get Diarrhea After Drinking Milk?

1. Lactose Intolerance

When there is a shortage of lactase, a kind of enzyme that is responsible for digesting lactose in your system, you will have lactose intolerance. Individuals who are lactose intolerant are unable to digest lactose in milk, so they typically develop diarrhea after drinking it. While the condition is not considered life-threatening, it can cause very unpleasant symptoms which usually appear 15 minutes to 2 hours after drinking milk or consuming other foods that contain lactose. Other common symptoms of lactose intolerance include:

• Abdominal cramps
• Bloating
• Nausea
• Vomiting
• Gas

2. Milk Allergy

A milk allergy occurs when you have a reaction to a milk protein, either whey or casein. Diarrhea is one of the most common symptoms of milk allergy. While milk from any mammal can cause the condition, cow’s milk is the most common culprit. Signs and symptoms typically surface between five minutes to three hours after eating or drinking food containing milk.

Immediate symptoms can include:

• Wheezing
• Hives
• Vomiting

Except from diarrhea, symptoms that develop after more time has passed include:

• Abdominal cramps
• Loose stools
• Bloody stools
• Running nose
• Coughing
• Skin rash, commonly around mouth

3. The Difference Between Lactose Intolerance and Milk Allergy

If you suffer from lactose intolerance, it means you have difficulty digesting the sugar in milk. It is a digestive system problem.

However, milk allergy is related with your immune system. In this condition, the antibody called immunoglobulin E takes proteins in milk as bad substances and tries to expel them out, causing immune responses.

Because they seem alike but are actually very different, you should not diagnose it on your own. Diarrhea after drinking milk is a symptom of both conditions and only a doctor can determine which one you are suffering from.

How to Prevent Diarrhea Caused by Lactose Intolerance

Lactose intolerance is not curable, but this does not mean it is not manageable. There are several ways to control your symptoms and avoid triggers. You may need to try a variety of techniques before finding the one that works for you.

1. Reduce Intake of Milk and Milk Products

The average person can have a daily amount of 10 g of lactose, so you should consume fat-free, skim, and low-fat milk that contain less lactose. You can also consider eating cheddar cheese which has only 0.9 g of lactose per serving. Experiment with a little bit at first to see how you react.

2. Consume Milk and Milk Products with Other Foods

Sometimes something as simple as consuming milk or milk products with another type of food will counteract lactose intolerant symptoms. For example, eating oatmeal with milk, or cheese with bread may alleviate the severity of your body’s reaction.

3. Eat or Drink Milk and Milk Products in Small Amounts

Instead of chowing down on a big hunk of cheese and washing it down with a tall glass of milk, consider eating small amounts of milk products throughout the day. Often, lactose intolerant people will find this eliminate symptoms.

4. Consider Products with Reduced Lactose

There are several types of reduced lactose milk products on the market. For some individuals, drinking this type of milk or eating products made from it does not trigger their symptoms. However, you should be careful if you have diabetes, because consumption of these products can raise sugar levels.

5. Replace Milk and Milk Products with Other Foods

There are several substitutes available, such as nondairy creamers, soy milk, almond milk, soy cheese and tofu. The thing to note is these products often do not have the same nutritional benefits as milk. 

6. Take Lactase Supplements

There are lactase dietary supplements that aid in the digestion of lactose. The supplement can be a pill chewed before consuming milk-based products or drinking milk. Some other supplements are liquids that can be added to milk before drinking. You can try different products and see which one is best for you and by this way, diarrhea after drinking milk will be greatly improved.

7. Completely Remove Lactose for Severe Lactose Intolerance

For many people with severe lactose intolerance, the only solution is completely removing lactose from diet. It is not easy because lactose can be found in all types of products including some medications, prepared foods and instant drinks. Some examples include instant breakfast drinks, instant soups, baked goods, pancake mix, salad dressing, milk chocolate and margarine. When you look at the ingredients on labels, look for words like:

• Whey
• Dry milk solids
• Milk by-products
• Curds
• Nonfat dry milk powder

Note: If you suffer from lactose intolerance and avoid anything related with milk, be sure to take supplements containing vitamin D, calcium, riboflavin and protein. You can also add foods rich in these nutrients to your diet to prevent a deficiency.

How to Prevent Diarrhea Caused by Milk Allergy

If you are suffering from diarrhea after drinking milk caused by milk allergy, the only way to combat it is avoiding milk. Because milk is a commonly used ingredient in several foods, this can be a difficult task. Some individuals can eat some products made with heated milk like baked foods, or processed milk like yogurt. Your physician can help you identify foods to steer clear of.

In case you do accidently eat something that contains milk, keep antihistamines nearby at all times to prevent allergic reactions and symptoms. This medication can help if taken immediately after the consumption of a milk product.

If your allergy is severe, you may suffer from anaphylaxis. This is a serious allergic reaction that can result in swelling throat and blocked airways. In this case, it is important to carry a life-saving injectable epinephrine with you all the time. Your doctor can instruct you on how to use it if ever needed in an emergency.