Why Do I Have Gas After Eating Salad?

Why Do I Have a Bad Stomachache After Eating Salad?

Why Do I Have a Bad Stomachache After Eating Salad?
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You may reach for salad as a healthy meal or side — but it might cause digestive problems, depending on what’s in it. Raw vegetables and fruits can cause bloating and gas, thanks to certain compounds and bacteria they may contain, which could be why you sometimes have a bad stomachache after eating salad.

Fiber Gets You Going

Fiber is a type of carbohydrate that passes through the body undigested.

It’s best known for promoting regular bowel movements, but that’s just one of its many benefits. It can bulk up to slow the absorption of glucose, fats, and cholesterol, or plow gently through your intestines to clean and clear out your tubes. It’s a key contributor to regular bowel movements.
There are two forms of fiber: soluble and insoluble. Soluble fiber dissolves in water, and it can help lower blood sugar and cholesterol levels.

Soluble fiber foods include:

  • Oatmeal
  • Nuts
  • Beans
  • Lentils
  • Apples
  • Blueberries
Insoluble fiber doesn’t dissolve in water, and it helps food move through the digestive system to prevent constipation.

Insoluble fiber foods include:

  • Wheat
  • Brown rice
  • Legumes
  • Carrots
  • Cucumbers
  • Tomatoes

“Salad vegetables contain indigestible cellulose, which is a type of insoluble fiber, meaning that much of what’s on your plate is indigestible,” says Boston-based Erin Kenney, RD, LDN, author of Rewire Your Gut and founder of Nutrition Rewired.

So, those salad veggies that help prevent constipation could also cause gas and bloating. Adding too much fiber to your diet too quickly may raise your risk of unpleasant side effects, as can having certain underlying health conditions, such as irritable bowel syndrome (IBS).

“Not chewing vegetables completely and [having] irritable bowel syndrome are a couple of conditions that can make it difficult to digest certain vegetables,” Kenney says.

The Dietary Guidelines for Americans 2020–2025 recommends that most adults eat 22 to 34 grams of fiber daily, though you may need more or less depending on your age, sex, and health status.

 It’s best to start low and go slow when adding fiber to your diet.

Hidden Causes of Discomfort

Select and prepare your fruits and vegetables safely when you’re putting together a salad. Germs on fresh produce are a cause of foodborne illnesses in the United States, according to the U.S. Department of Health and Human Services (DHHS).

For instance, “Iceberg lettuce might be contaminated with a disease-causing bacteria, such as E. coli,” Kenney says. “It’s important to always thoroughly wash your produce, even if the package says it’s been prewashed.” To prevent foodborne illnesses, DHHS also recommends you:

  • Choose products that aren’t bruised or damaged.
  • Wash your hands before preparing produce.
  • Get rid of damaged areas, including torn or bruised leaves.
  • Remove the outer leaves of cabbages and lettuce heads.
  • Dry produce with a clean paper towel.
  • Keep precut fruits and vegetables cold, and refrigerate them within two hours of cutting or cooking them.
  • Separate fruits and vegetables from any raw meat, poultry, and seafood.
If you have a bad stomachache after eating salad, food poisoning could potentially be the cause. The Centers for Disease Control and Prevention describes food poisoning symptoms as:

  • Nausea
  • Stomach cramps
  • Vomiting
  • Diarrhea

If you chew well, keep your stress down, and clean your veggies, you’ll have a better chance of avoiding that type of tummy discomfort. But beware of another potential threat, known as FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols).

Swap Out Fruits and Veggies That Are High in FODMAPs

Many fruits and vegetables contain carbohydrates that are especially hard to absorb in your small intestine, which can create gas and cause IBS symptoms to flare.

Specifically, these are called FODMAPs.

“These short-chain carbohydrates resist digestion, and instead of being absorbed into your bloodstream, they make their way to the colon, where they ferment and create gas,” Kenney says. “They then pull water into the intestinal tract, which builds up, causing bloating, cramping, pain, and diarrhea/constipation.”

The body is designed to handle indigestible foods, and FODMAPs aren’t bad news for everyone.

 However, they may cause problems for people with sensitive guts, including those with IBS.
Common high-FODMAP fruits and vegetables you may find in a salad include:

  • Apples
  • Mushrooms
  • Sugar snap peas
  • Cabbage
  • Broccoli
  • Onion
  • Cauliflower
  • Cherries
  • Dried fruit
  • Avocados
  • Pears
Following a low-FODMAPs diet (limiting your intake of these foods) has been shown to improve IBS symptoms in about 75 percent of patients.

“If you suspect FODMAPs might be an issue for you, be sure to work with a registered dietitian to ensure you’re getting adequate nutrition while resolving your gastrointestinal symptoms,” Kenney says. There are also gentler versions of the low-FODMAP diet that you can discuss as well, which will restrict fewer foods.

The Takeaway

  • Salads are a nutritious part of a healthy diet, but they sometimes cause unpleasant side effects, such as gas, bloating, and diarrhea.
  • You’re more likely to experience these symptoms if you add lots of fiber to your diet quickly, have a condition such as IBS, or eat spoiled or damaged produce.
  • If you suspect that certain foods are causing you stomach trouble, talk with a dietitian or other qualified healthcare provider.
EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
  1. Fiber. Harvard T.H. Chan School of Public Health. April 2022.
  2. Dietary Fiber: Essential for a Healthy Diet. Mayo Clinic. December 11, 2024.
  3. Dietary Guidelines for Americans 2020–2025. U.S. Department of Agriculture. December 2020.
  4. Fruit and Vegetable Safety. FoodSafety.gov.
  5. Symptoms of Food Poisoning. Centers for Disease Control and Prevention. January 31, 2025.
  6. Low FODMAP Diet. Cleveland Clinic. February 24, 2022.
  7. Low FODMAP Diet. Mount Sinai.
  8. Collins L et al. A FODMAP Gentle Approach. Monash University. February 24, 2020.

Yuying Luo, MD

Medical Reviewer

Yuying Luo, MD, is an assistant professor of medicine at Mount Sinai West and Morningside in New York City. She aims to deliver evidence-based, patient-centered, and holistic care for her patients.

Her clinical and research focus includes patients with disorders of gut-brain interaction such as irritable bowel syndrome and functional dyspepsia; patients with lower gastrointestinal motility (constipation) disorders and defecatory and anorectal disorders (such as dyssynergic defecation); and women’s gastrointestinal health.

She graduated from Harvard with a bachelor's degree in molecular and cellular biology and received her MD from the NYU Grossman School of Medicine. She completed her residency in internal medicine at the Icahn School of Medicine at Mount Sinai, where she was also chief resident. She completed her gastroenterology fellowship at Mount Sinai Hospital and was also chief fellow.

Lauren Armstrong, RDN

Author

Lauren is a Registered Dietitian with over 6 years of experience in the field. She has experience in food service management, nutrition counseling, and WIC. Lauren graduated from Western Michigan University and completed her dietetic internship at Michigan State University. You can see her writing work at www.laurenarmstrongrdn.com