Is Ensure Bad for an Upset Stomach?

November 9, 2025 •

4 min read

While designed as a balanced nutritional supplement, it's a common observation among users that Ensure can sometimes worsen an upset stomach. The potential for digestive distress is tied to certain ingredients and individual sensitivities, which can lead to bloating, gas, and cramps. For those with pre-existing digestive sensitivities or conditions like IBS, understanding these potential side effects is key to avoiding further discomfort.

Quick Summary

This guide examines whether Ensure can be problematic for a sensitive or upset stomach. We explore the ingredients that may cause digestive issues, common side effects, and offer alternative options for nutrition when experiencing gastric distress. We also discuss when to consult a healthcare provider for persistent symptoms.

Key Points

Identify the Cause: Ensure's ingredients, like milk protein concentrate, soy, and sugar, can irritate sensitive stomachs and cause issues like bloating and diarrhea.
Assess Personal Intolerances: Conditions such as lactose intolerance are common, and Ensure's dairy content can be a major culprit for discomfort, especially in older adults.
Try Homemade Alternatives: Making customizable smoothies with stomach-friendly ingredients like bananas, almond milk, and mild protein powder can be a gentler option.
Monitor Your Symptoms: Keep track of digestive reactions to identify if Ensure or specific ingredients are causing a problem before making changes.
Consult a Professional: For persistent or severe digestive issues, including prolonged diarrhea or blood in stool, it is crucial to seek medical advice.
Consider Alternative Products: Other supplements with different formulations exist; always read labels carefully and talk to a healthcare provider for recommendations.
Adjust Gradually: If your body is new to Ensure, side effects like digestive upset might subside after a few days as your system adjusts.

Understanding How Ensure Can Affect a Sensitive Stomach

Ensure is a well-known nutritional supplement that provides a wide range of vitamins, minerals, and protein. For many, it's a convenient and effective way to get necessary nutrients, especially during recovery or when appetite is low. However, its formulation can be a double-edged sword, and for some, it can lead to or worsen an upset stomach. Several factors contribute to this, with individual intolerances playing a significant role.

Potential Irritants and Side Effects

Several components in Ensure can cause issues for sensitive digestive systems. These potential irritants include:

Milk Protein Concentrate: Many Ensure products contain milk protein concentrate, which can be problematic for individuals with lactose intolerance. Lactose intolerance, where the body can't properly digest the sugar in milk, is a widespread condition, particularly among older adults. Symptoms include bloating, gas, cramps, and diarrhea.
Sugar and Artificial Sweeteners: Some Ensure formulas can contain significant amounts of added sugar, such as corn maltodextrin, which can trigger digestive discomfort in some individuals. Additionally, artificial sweeteners found in certain varieties can have a laxative effect.
Soy Protein: As many Ensure varieties contain soy protein isolate, those with a soy allergy or sensitivity may experience negative reactions. Symptoms can range from mild digestive upset to more severe allergic responses.
Carrageenan: This is a food additive used as a thickener and stabilizer in many Ensure products. While approved for use, some people report digestive issues, including inflammation, after consuming it.
Corn Maltodextrin: A type of carbohydrate derived from corn, maltodextrin is used as a thickener. Some individuals may experience indigestion or bloating from this ingredient, particularly if they are sensitive to corn-based products.

Common Digestive Complaints from Ensure

Based on user reports and some clinical observations, the most common digestive side effects linked to Ensure consumption include:

Diarrhea
Nausea
Bloating and gas
Constipation (often in early stages of use or due to ingredients like iron)
Stomach cramps

These symptoms are typically mild and may resolve after the body adjusts to the supplement, but for those with already compromised digestive systems, they can be a major problem.

When to Consider Alternatives or Modifications

If you find that Ensure consistently causes digestive upset, it's wise to explore other options. The right choice depends on the specific cause of your stomach sensitivity.

Comparison Table: Ensure vs. DIY Smoothies


Feature	Ensure	Homemade Smoothies
Ingredients	Processed, pre-mixed with synthetic vitamins and thickeners. May contain sugar, soy, and dairy.	Customizable using whole foods like fruits, vegetables, yogurt, and protein powder.
Control	No control over ingredients.	Full control over ingredients, allowing for personalization based on intolerances.
Nutrient Density	Formulated for balanced nutrition, but relies on processed components.	Can be highly nutrient-dense with the right combination of whole foods.
Fiber Content	Can vary; some versions include prebiotic fiber, others have low fiber.	Customizable fiber content, which can be adjusted for sensitive stomachs.
Cost	Convenient but can be expensive over time.	Generally less expensive, depending on ingredients used.
Digestive Impact	Can cause bloating, gas, or diarrhea in some individuals due to specific ingredients.	Can be gentler on the stomach, especially when using easy-to-digest ingredients.

Homemade Smoothies for Sensitive Stomachs

Creating your own nutrient-rich drinks with whole foods is an excellent way to get nutrition while avoiding potential irritants. This offers the ultimate control over ingredients, ensuring everything is gentle on your system. Here are some stomach-friendly ingredients you can use:

Base Liquids: Water, almond milk, or lactose-free milk are great choices.
Fruits: Bananas and applesauce are easy to digest and can provide soothing fiber.
Protein: For a non-dairy option, consider a plant-based protein powder or tofu.
Healthy Fats: Add a little avocado for creaminess and healthy fats.
Probiotics: Plain yogurt or kefir (if dairy is tolerated) can help restore gut flora.

Other Nutritional Supplements

If making your own smoothies is not feasible, there are other supplement brands that may be better tolerated. Some brands offer special formulations that are dairy-free, soy-free, or lower in sugar. Always read the ingredient list carefully and look for products designed for sensitive digestive systems. The best course of action is to discuss your options with a healthcare provider or a registered dietitian.

When to See a Doctor

While an upset stomach can often resolve on its own, certain symptoms warrant a visit to a healthcare provider. You should seek medical advice if you experience:

Severe, persistent, or chronic abdominal pain
Persistent vomiting
Diarrhea lasting more than two days
Blood in your stool or vomit
Unexplained weight loss

These symptoms can indicate a more serious underlying condition that requires professional medical attention. Always consult with a healthcare provider before making major changes to your diet or supplementing, especially if you have pre-existing health conditions or are taking other medications.

Conclusion

While Ensure serves as a valuable nutritional tool for many, it is not a universally suitable option for all, especially those with sensitive digestive systems. Ingredients such as milk protein concentrate, sugar, and soy can cause discomfort, including bloating, gas, and diarrhea. If you suspect Ensure is the cause of your upset stomach, consider switching to homemade, customizable smoothies made with easy-to-digest ingredients. Consulting a healthcare professional can also help you find a suitable alternative that meets your nutritional needs without triggering digestive distress. For more on digestive health, see the NIH's resources.

Frequently Asked Questions

Ensure can cause an upset stomach due to its ingredients, which may include milk protein concentrate, soy protein, and added sugars or sweeteners. People with lactose intolerance, soy allergies, or sensitive digestive systems might experience bloating, gas, or diarrhea.

Yes, Ensure does offer some lactose-free formulations that are suitable for people with lactose intolerance. It is important to check the product label to ensure it is the lactose-free version.

While Ensure is generally considered easy to digest for most people, some individuals with sensitive stomachs or specific intolerances may find certain ingredients difficult to process, leading to digestive upset. Many formulas contain milk or soy, which are common irritants.

For a sensitive stomach, consider alternatives like homemade smoothies using easy-to-digest ingredients such as bananas, low-fat yogurt (if tolerated), and plant-based milk. There are also other commercial nutritional supplements specifically formulated for sensitive digestive systems.

Yes, Ensure can cause diarrhea in some individuals. This may be due to ingredients like milk protein for those with lactose intolerance, artificial sweeteners, or other additives.

Some users and health blogs have pointed to ingredients like carrageenan and certain oils used in some Ensure formulas as potential inflammatory agents. However, the effects vary significantly between individuals and often depend on overall dietary habits and sensitivities.

You should stop drinking Ensure and consult a doctor if your upset stomach is severe, persistent, or accompanied by symptoms like chronic pain, bloody stools, or unexplained weight loss. A healthcare provider can help determine the root cause of your digestive issues.

Yes, some Ensure products are specifically low in sugar, and other brands offer similar low-sugar, high-protein supplements. You can also control sugar content entirely by opting for a homemade smoothie with natural fruits and less added sweetener.