Can Molasses Cause Stomach Issues? A Look at Gut Health and Digestion

November 14, 2025 •

3 min read

Over one-third of people report experiencing bloating and digestive discomfort regularly. For those with sensitive stomachs, a natural sweetener like molasses might seem like a healthy alternative, but it can sometimes cause stomach issues.

Quick Summary

Molasses can trigger stomach issues like bloating, gas, and diarrhea, especially in sensitive individuals due to its high fermentable carbohydrate (FODMAP) content. The high sugar concentration and laxative effect, particularly in blackstrap molasses, can cause digestive upset when consumed in excess. Moderation is key, and individuals with IBS or fructan sensitivities should be cautious. Alternatives like maple syrup or table sugar may be safer options for those prone to digestive problems.

Key Points

High FODMAP Content: Molasses contains high levels of fructans and excess fructose, fermentable carbohydrates that can trigger bloating and gas in sensitive individuals.
Natural Laxative Effect: Especially in blackstrap molasses, the high magnesium content can have a laxative effect, causing loose stools or diarrhea when consumed in excess.
Sugar Load Overload: The high sugar content can lead to fermentation by gut bacteria, which produces gas and results in abdominal discomfort and bloating.
IBS Trigger: Due to its fermentable carbohydrates, molasses is generally not recommended for people on a low-FODMAP diet or those with IBS.
Individual Tolerance Varies: While some can tolerate small amounts, others may experience significant symptoms; portion control is critical.
Better Alternatives: For those with digestive sensitivities, alternatives like pure maple syrup or white sugar are considered low-FODMAP and may be safer options.

Understanding Molasses and Its Composition

Molasses is a thick, dark syrup created as a byproduct of the sugar refining process, most commonly from sugarcane or sugar beets. The boiling process concentrates the remaining minerals, resulting in a nutrient-rich sweetener, especially blackstrap molasses, which is a source of iron, calcium, and magnesium. While these nutrients can offer health benefits, the high concentration of certain carbohydrates is where digestive problems can arise.

The Role of FODMAPs in Molasses and Digestion

FODMAPs, or Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols, are short-chain carbohydrates that can be poorly absorbed in the small intestine. Molasses is considered a high-FODMAP food, largely because it contains significant amounts of fructans.

For individuals with Irritable Bowel Syndrome (IBS) or fructan sensitivity, consuming high-FODMAP foods can lead to digestive distress. The unabsorbed fructans travel to the large intestine, where gut bacteria ferment them, producing gas and causing symptoms like bloating, cramping, and discomfort. This fermentation process can be particularly troublesome for those with a sensitive gut microbiome. Molasses also contains varying levels of free fructose and sucrose, which can further compound the issue for those with fructose intolerance or sucrase deficiency.

How Molasses Can Act as a Laxative

Another factor contributing to digestive upset is the laxative effect of molasses, especially blackstrap molasses. This is primarily due to its high magnesium content. Magnesium is a mineral that, when consumed in high doses, can draw water into the intestines, softening stool and promoting bowel movements.

Constipation relief: While this property can be beneficial for occasional constipation, it can cause diarrhea if consumed in large quantities.
Diarrhea risk: For those with an already sensitive digestive system or conditions like IBS, the laxative effect can be too strong, leading to loose stools or diarrhea.

The Impact of Sugar Load and Fermentation

Beyond the FODMAP content, the sheer sugar load in molasses can also cause problems. The high levels of sucrose, which is composed of glucose and fructose, can lead to sugar overload in the digestive system. When the body has difficulty absorbing these sugars, they become food for gut bacteria, leading to gas and bloating.

Comparison Table: Molasses vs. Refined Sugar and Maple Syrup


Feature	Molasses	Refined White Sugar	Maple Syrup
FODMAP Content	High (due to fructans and excess fructose)	Low (safe for low FODMAP diets)	Low (fructose is balanced with glucose)
Nutrient Density	High (iron, calcium, magnesium, potassium)	None (empty calories)	Moderate (potassium, calcium)
Digestive Effect	Can cause bloating, gas, diarrhea (especially in large amounts)	Generally no digestive issues from sugar itself	Mild, generally well-tolerated, some can find it mildly laxative
Laxative Effect	Moderate to strong (especially blackstrap due to magnesium)	None	Very mild to none

Limiting Molasses for Digestive Comfort

If you experience digestive issues after consuming molasses, there are a few strategies to minimize the effects:

Start small: Test your tolerance with a very small amount, like half a teaspoon, and see how your body reacts. Some people can tolerate small servings.
Use alternatives: For those on a low-FODMAP diet or with known sensitivities, low-FODMAP sweeteners like pure maple syrup or regular table sugar may be better options.
Consider type: Blackstrap molasses has the most robust flavor and the highest mineral concentration, including magnesium. Lighter molasses varieties may be better tolerated due to their lower mineral content.
Consult a professional: For persistent digestive issues, it is always recommended to consult a healthcare professional or a registered dietitian who can provide personalized advice.

Conclusion

While molasses is a more nutrient-dense alternative to refined sugar, it is not without its potential for digestive distress. The presence of fermentable carbohydrates (FODMAPs), excess fructose, and a natural laxative effect from magnesium can trigger stomach issues like bloating, gas, and diarrhea, particularly in sensitive individuals or when consumed in large quantities. Understanding your own body's tolerance and approaching it in moderation is the key to enjoying this rich sweetener without the unwanted side effects. For those with significant digestive sensitivities, exploring alternative sweeteners is a wise course of action.

Frequently Asked Questions

Molasses can cause bloating because it is high in FODMAPs, particularly fructans and excess fructose. These carbohydrates are poorly absorbed in the small intestine and are fermented by gut bacteria in the large intestine, which produces gas and leads to a bloated sensation.

Yes, blackstrap molasses has a known laxative effect. This is largely due to its high magnesium content, a mineral that helps promote bowel movements by drawing water into the intestines.

Generally, it is not recommended to consume molasses if you have Irritable Bowel Syndrome (IBS). Its high FODMAP content is a common trigger for IBS symptoms like bloating, gas, and abdominal pain. Small amounts may be tolerable for some, but a low-FODMAP diet usually suggests avoiding it.

Moderation is key, and individual tolerance varies. For some, as little as one teaspoon can cause a reaction, while others may tolerate up to a tablespoon. It is best to start with a very small amount and monitor your body's reaction.

For individuals with sensitivities to FODMAPs or excess fructose, molasses can be hard to digest. The unabsorbed sugars ferment in the gut, leading to the production of gas and other uncomfortable digestive symptoms.

The most common stomach issues linked to molasses consumption are bloating, gas, abdominal cramping, and diarrhea, especially when consumed in larger quantities.

If you are sensitive to molasses, low-FODMAP alternatives like pure maple syrup, rice malt syrup, or regular table sugar are safer choices for sweetening. Adding warm spices like cinnamon and ginger can mimic the flavor profile without the digestive risk.