Do Prunes Actually Help with Bowel Movements? The Surprising Science

October 5, 2025 •

4 min read

For centuries, prunes have been a trusted folk remedy for constipation, and modern science confirms their effectiveness. Research shows that consuming prunes can increase bowel movement frequency and improve stool consistency, often outperforming even popular fiber supplements.

Quick Summary

Prunes contain a powerful trio of fiber, sorbitol, and phenolic compounds that work synergistically to alleviate constipation and promote regular bowel movements. Their combined effects bulk and soften stool, draw water into the intestines, and support a healthier gut microbiome. Whole prunes are generally more effective than juice due to higher fiber content, but juice retains beneficial sorbitol.

Key Points

Proven Effectiveness: Prunes are scientifically supported as an effective dietary approach for mild to moderate constipation, sometimes outperforming fiber supplements like psyllium.
Triple-Action Mechanism: Their effect is linked to a combination of soluble and insoluble fiber for bulk and softness, sorbitol to draw water into the intestines, and polyphenols that may aid digestion and gut health.
Whole Fruit Contains More Fiber: Whole prunes generally contain more fiber than prune juice, which contributes significantly to stool bulk.
Gradual Introduction is Key: When adding prunes or prune juice to your diet, starting with a smaller serving size is often advised to help your digestive system adjust and minimize potential gas or bloating.
Hydration is Essential: Adequate fluid intake is crucial when consuming prunes or any high-fiber food to ensure the fiber and sorbitol function correctly; dehydration can exacerbate constipation.
Support Beyond Digestion: The compounds in prunes, including fiber and polyphenols, are thought to contribute to a healthier gut microbiome, which benefits overall health beyond just regularity.

The Scientific Breakdown of Prunes

Prunes (dried plums) are a nutritional powerhouse for the gut, providing a multi-pronged approach to relieving constipation. The primary mechanisms are their fiber content, high sorbitol levels, and beneficial phenolic compounds.

Fiber: The Bulk and Softness

Prunes are an excellent source of dietary fiber, offering both soluble and insoluble types.

Soluble fiber: This type dissolves in water to form a gel-like substance. This softens the stool, making it easier to pass, and helps to slow digestion for balanced nutrient absorption.
Insoluble fiber: This fiber remains mostly intact as it travels through the digestive tract. It adds bulk to the stool, which helps to speed up its movement through the intestines.

Sorbitol: The Natural Laxative Effect

One of the most potent components of prunes is sorbitol, a sugar alcohol that is naturally resistant to digestion. When it reaches the large intestine, it draws water in from the body. This influx of water has a mild osmotic effect, further softening the stool and stimulating bowel movements. Consuming large amounts of sorbitol can sometimes cause diarrhea and gas.

Phenolic Compounds: Antioxidant and Gut Support

Prunes are rich in phenolic compounds, which are antioxidants that may enhance the laxative effects of fiber and sorbitol. Some studies also suggest these compounds and the fiber in prunes have a prebiotic effect, supporting a healthier gut microbiome by feeding beneficial bacteria. This process can generate short-chain fatty acids, which also contribute to gut health and may lower the risk of constipation.

Whole Prunes vs. Prune Juice: A Comparison

While both whole prunes and prune juice can help with constipation, there are key differences in their composition and effectiveness.


Feature	Whole Prunes	Prune Juice	Comparison
Fiber Content	High (contains both soluble and insoluble fiber)	Low (soluble fiber is mostly lost during juicing)	Whole prunes offer superior fiber benefits for bulking stool.
Sorbitol Content	Higher concentration (approx. 14.7g per 100g)	Lower concentration (approx. 6.1g per 100g)	Whole prunes provide a more concentrated dose of the osmotic substance.
Nutrient Density	Higher overall, with more vitamins and minerals per calorie	Lower, some nutrients are lost in processing	Whole prunes are generally a more nutrient-dense option.
Speed of Effect	Generally slower, as the body needs to digest the fruit	Potentially faster for immediate relief, as it passes through the digestive system quicker	Juice can potentially offer quicker results, while whole prunes may support longer-term regularity.
Side Effects	Can cause bloating/gas if consumed in excess	Can cause bloating/gas if consumed in excess; higher sugar/calorie density	Both can cause discomfort if overconsumed, but individual tolerance varies.

How to Incorporate Prunes into Your Diet

When incorporating prunes or prune juice into your diet for digestive support, starting with a small amount is often recommended to assess tolerance and avoid potential gastrointestinal discomfort. Increasing water intake alongside prune consumption can also be beneficial as it supports the action of fiber and sorbitol in the digestive system. It may take some time for the body to adjust to the increased fiber and sorbitol, so patience is key.

Potential Side Effects and When to Be Cautious

While prunes are generally considered a safe and natural option, some individuals may experience side effects. The high fiber and sorbitol content can lead to gas, bloating, and even diarrhea if consumed in large quantities. Individuals with conditions like Irritable Bowel Syndrome (IBS) or those following a low-FODMAP diet should be cautious, as prunes are high in sorbitol and fructans, which can worsen symptoms for some people. If persistent constipation or other digestive issues continue, or if you have underlying health conditions, it is best to consult a healthcare professional.

Alternatives to Prunes

If prunes are not your preference or cause side effects, many other natural foods can promote healthy bowel movements. These include:

Kiwifruit: Contains fiber and an enzyme called actinidin that supports digestion.
Berries: Sources of both soluble and insoluble fiber.
Chia and Flaxseeds: Excellent sources of fiber that form a gel to soften stool when mixed with liquid.
Legumes: Beans, lentils, and chickpeas are high in fiber.
Hydration: Drinking plenty of water is crucial for all forms of fiber to work effectively and is vital for preventing constipation.

Conclusion

Yes, the conventional wisdom holds true: prunes are a proven, effective, and safe dietary approach for mild to moderate constipation. Their unique blend of fiber, sorbitol, and polyphenols offers a comprehensive approach to supporting regularity that can be more effective than some single-ingredient fiber supplements. While whole prunes often provide more overall nutritional benefits and fiber, prune juice can offer quicker potential relief due to its more rapid passage through the digestive system. As with any dietary change, incorporating prunes gradually and ensuring adequate hydration are important steps to support digestive health and minimize potential side effects. A balanced diet rich in varied fiber sources, coupled with plenty of water, is the best long-term strategy for maintaining healthy digestive function.

For more in-depth research on dried plums and their effect on constipation, a comprehensive review of randomized controlled trials was published in the journal Alimentary Pharmacology & Therapeutics.

Frequently Asked Questions

The timeframe for prunes to have an effect varies among individuals. Some may notice changes within a few hours, while others might take a day or more to experience results.

Whole prunes are generally recommended due to their higher fiber content, including both soluble and insoluble fiber, which adds bulk to the stool. Prune juice retains sorbitol but loses much of the insoluble fiber during processing.

Adults often start by incorporating a small number of whole prunes or a moderate amount of prune juice into their daily diet. It is advisable to begin with a small serving to see how your body reacts and increase gradually if needed.

Consuming too many prunes can lead to common side effects such as gas, bloating, and diarrhea, primarily due to their fiber and sorbitol content. Starting with a smaller serving size and staying hydrated can help manage these effects.

Yes, individuals with sensitive stomachs or conditions like IBS should approach prunes with caution. Prunes are relatively high in FODMAPs like sorbitol, which can potentially trigger digestive discomfort such as gas and bloating in sensitive individuals.

Beyond fiber and sorbitol, prunes contain phenolic compounds, which are antioxidants that may support the laxative effect. These compounds, along with the fiber, can also act as prebiotics, benefiting the gut microbiome.

Clinical studies suggest that prunes can be effective for treating mild to moderate constipation, and some research indicates they may lead to more frequent and better-formed stools compared to psyllium husk.