Does Chocolate Cause Stomach Upset?

If all you need is love and chocolate but the latter upsets your stomach — or worse, causes nausea and diarrhea — that's a chocolate craving gone bad. Uncovering the possible cause, from food sensitivities to underlying health conditions, could get you back on track.

There are many different versions of chocolate, from dark to milk to white; bitter to sweet; and everything in between. How your body reacts may reflect your chocolate choice.

If it's milk chocolate you've been noshing on when symptoms strike, the lactose (milk sugar) content could be suspect No. 1. In fact, lactose intolerance strikes about 65 percent of the population, according to the U.S. National Library of Medicine.

Per Mayo Clinic, if you can't digest lactose (aka lactose intolerance) and you consume lactose (think milk chocolate), tummy troubles may ensue — from gas and bloating to diarrhea. These symptoms usually begin within 30 minutes to two hours. That could be a helpful indicator in determining whether your sweet chocolate treat is the cause of your stomach upset.

Notably, how much lactose is in that milk chocolate snack you're savoring varies by brand, but, given its name, all milk chocolate is made with milk. Ergo, depending on your relationship with lactose, if you suspect lactose as the source of your upset stomach, you could swap brands, grab a dairy-free option or try a dark chocolate alternative.

​Read more:​ Is Dark Chocolate Healthier Than Milk Chocolate?

If your body digs digesting lactose, a food sensitivity could be what's causing that tummy upset instead. According to Boston-based dietitian and nutritionist Erin Kenney, RD, LDN, sensitivities to a specific food can cause such symptoms as:

• Bloating.
• Constipation.
• Diarrhea.
• Lethargy.
• Rashes and/or eczema.

"Food chemicals are a type of food sensitivity that can cause IBS (irritable bowel syndrome) symptoms," Kenney says. "If we consume high amounts of these foods, such as chocolate, we can find a histamine type response that can irritate the nerve endings in the gut."

Alternatively, full-on food allergies, according to Mayo Clinic, may be severe and can trigger a life-threatening immune response. So, food for thought: Got milk… in your chocolate? According to the Food and Drug Administration (FDA), milk is one of the top eight major food allergens. It's also not exclusively an ingredient in milk chocolate varieties. As the FDA notes, milk is a permissible ingredient in dark chocolate.

While some dark chocolate products are made sans milk, the dairy ingredient has been found in some selections, usually as the result of shared equipment.

So what if the label explicitly states dairy-free? Not so fast. While products labeled as such should not contain dairy, the FDA released a survey suggesting otherwise. The 2018-19 survey examined 52 dark chocolate bars labeled dairy-free, and four of them included potentially hazardous levels of milk allergens — and at high enough levels to cause severe allergic reactions.

While the FDA is on the case, in the meantime, if you have a milk allergy, go the extra mile to keep yourself (and your chocolate habit) safe by checking the ingredient list and reading all label statements.

If you don't fit the bill for lactose intolerance, food sensitivities or a milk allergy, your gut could be responsible for that chocolate-induced sour stomach.

According to Cleveland Clinic, upward of 15 percent of the U.S. adult population has irritable bowel syndrome, classified as the most commonly diagnosed GI disease — but as few as 5 percent are diagnosed. IBS is characterized by a group of digestive symptoms like abdominal cramping, chronic diarrhea, excessive gas and more, and can be triggered by a number of factors, including the foods you consume.

One such food offender is — you guessed it — chocolate. According to the Cleveland Clinic, the caffeine in chocolate can serve as a trigger that exacerbates symptoms and thus should be avoided.

Ultimately, a good rule of thumb is to avoid foods that cause you gastrointestinal upset and schedule an appointment with your doctor to ensure you have no underlying condition causing those uncomfortable symptoms.

​Read more:​ 11 Foods to Avoid When You Have IBS