What foods can cause bloating?

Foods That Cause Bloating

The most common dietary culprits for bloating are lactose-containing dairy products (affecting 51% of bloating patients), fructose-rich foods (affecting 60%), artificial sweeteners including sugar alcohols and sorbitol, and fructans found in wheat and other gluten-containing grains. 1, 2

Primary Food Categories That Cause Bloating

Dairy Products and Lactose

• Milk and dairy products containing lactose are the most prevalent dietary cause of bloating, affecting up to 80% of blacks and Latinos, up to 100% of American Indians and Asians, and up to 15% of persons of northern European descent 3
• Lactose intolerance occurs when undigested lactose creates osmotic effects in the colon, leading to bloating, abdominal pain, excessive gas, and watery stools 1, 3
• Hard and semi-hard cheeses contain no lactose and are well-tolerated, while soft cheeses contain lactose in only 10% of cases 4
• Yogurt with live cultures is generally well-tolerated despite containing lactose, because the bacteria survive stomach passage and provide their own lactase enzyme 4
• Most lactose-intolerant individuals can tolerate up to 12 oz of milk daily without symptoms 3

Fructose-Containing Foods

• Fructose intolerance affects 60% of patients with bloating, making it even more common than lactose intolerance 1, 2
• Excessive intake of fruits high in fructose can cause bloating due to slow or incomplete absorption 1
• The prevalence is similar across most digestive disorders except IBS with constipation 1, 2

Artificial Sweeteners

• Sugar alcohols and sorbitol cause bloating through malabsorption mechanisms 1, 2
• These are commonly found in sugar-free products, chewing gum, and diet foods 1

Gluten-Containing Foods and Fructans

• Wheat, barley, and rye contain fructans that may be the actual culprit in many patients who believe they have gluten sensitivity 1, 5
• In patients with self-reported nonceliac gluten sensitivity, fructans in gluten-rich foods rather than gluten itself often cause the symptoms 1
• Foods high in fructans include cereals, grains, and certain vegetables 1, 2

High-Fiber and Indigestible Carbohydrates

• Excessive intake of indigestible carbohydrates can cause bloating, particularly in those with visceral hypersensitivity 1
• A high fiber intake can increase bloating and flatulence, especially in patients with ileostomies or functional bowel disorders 1
• However, fiber intake should be individualized—some constipated patients benefit from increased fiber while others with stricturing disease need to limit it 1

Other Dietary Triggers

• Caffeine in excessive amounts may contribute to bloating symptoms 1
• Gas-producing foods should be avoided in patients with flatulence, though specific foods vary by individual 1
• Carbonated beverages can introduce excess gas and should be avoided 1

Diagnostic Approach to Food-Related Bloating

Initial Assessment Strategy

• A 2-week dietary restriction trial is the simplest and most economically sound diagnostic approach, with symptom resolution serving as a positive predictor 1, 2
• Keep a two-week diary of symptoms, stresses, and dietary intake to identify aggravating factors 1
• For lactose intolerance, consider testing only if intake exceeds 0.5 pint (280 ml) milk per day 1

When to Consider Breath Testing

• Hydrogen-based breath testing measuring hydrogen, methane, and CO2 is reserved for patients refractory to dietary restrictions first 1
• This can diagnose lactose, fructose, or sucrose intolerances 1
• Breath testing is also used to diagnose small intestinal bacterial overgrowth (SIBO) with glucose or lactulose 1, 5

Celiac Disease Screening

• Test tissue transglutaminase IgA and total IgA levels in patients with IBS with diarrhea or alarm symptoms (weight loss, iron-deficiency anemia) 1
• Small bowel biopsy is required if serology is positive before starting treatment 1

Treatment Approach Based on Food Type

For Lactose Intolerance

• Prefer low-lactose or lactose-free milk rather than complete dairy avoidance 1
• Hard and semi-hard cheeses are safe alternatives 4
• Yogurt with live cultures is generally well-tolerated 4
• Lactase enzyme supplements may be helpful 3

For Fructose and Fructan Intolerance

• Eliminate fructans only rather than all gluten if fructans are the suspected trigger 1
• Reduce intake of high-fructose fruits if excessive 1
• A low FODMAP diet (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) may provide relief 1, 6

For Artificial Sweetener Sensitivity

• Avoid sugar alcohols and sorbitol found in sugar-free products 1
• Eliminate chewing gum which can also cause aerophagia 1

Critical Pitfalls to Avoid

• Do not allow patients to adopt inappropriately restrictive diets without proper guidance, as this can lead to nutritional deficiencies 1
• Do not assume all bloating is food-related—visceral hypersensitivity in IBS patients means they experience symptoms at lower thresholds even with normal food intake 1, 2
• Do not ignore alarm symptoms (weight loss >10%, iron-deficiency anemia, family history of inflammatory bowel disease) that warrant further investigation beyond dietary modification 1
• In women 50 years or older with new-onset bloating, consider ovarian cancer as bloating and abdominal fullness are often presenting symptoms 1, 5