What foods or supplements can cause diarrhea?

Foods and Supplements That Cause Diarrhea

Multiple dietary components and supplements can trigger diarrhea, with artificial sweeteners (especially sorbitol), high-fat foods, dairy products, caffeine, alcohol, and high simple sugar foods being the most common culprits. 1

Primary Dietary Triggers

Artificial Sweeteners and Sugar Alcohols

• Sorbitol, xylitol, mannitol, and other polyols found in sugar-free products, chewing gum, diet drinks, and diabetic foods cause osmotic diarrhea when consumed in amounts exceeding 50-60 g/day 2, 3
• These sugar alcohols are poorly absorbed in the small intestine and pass unchanged into the colon, where they draw water into the lumen and undergo bacterial fermentation 3
• Erythritol is better tolerated than other sugar alcohols due to its smaller molecular weight 3
• Complete elimination of sorbitol-containing products is recommended during diarrheal episodes 1

High-Fat Foods

• Fatty and fried foods are among the most frequent triggers of diarrhea, as they delay gastric emptying and can overwhelm fat absorption capacity 1
• Fat malabsorption leads to steatorrhea, particularly after malabsorptive bariatric procedures, causing deficiencies in fat-soluble vitamins, zinc, copper, and magnesium 4

Dairy Products and Lactose

• Milk and most dairy products (except yogurt and firm cheeses) should be avoided due to acquired lactase deficiency that commonly occurs during diarrheal illness 1, 4
• Primary lactase deficiency affects 68% of the world's population, with prevalence varying by ethnicity (2-15% in Northern European Caucasians) 4
• Lactose malabsorption occurs in up to 88% of patients with rotavirus diarrhea, though not all develop clinical symptoms 4

Beverages

• Coffee, tea, and caffeinated drinks should be restricted to maximum 3 cups daily or eliminated entirely during acute episodes 1
• All alcoholic beverages and carbonated/fizzy drinks should be avoided 1
• Soft drinks and undiluted fruit juices high in simple sugars exacerbate diarrhea through osmotic effects 4, 5

Carbohydrate-Related Triggers

FODMAPs (Fermentable Carbohydrates)

• Fructose in excess of glucose absorption capacity (common in corn syrup-sweetened soft drinks) causes malabsorption and colonic fermentation 4
• Fructans present in high concentrations in wheat products (bread, noodles) cause "wheat intolerance" in many patients without celiac disease 4
• Undigested fructose and fructans pass into the colon where bacterial fermentation produces gas and osmotic diarrhea 4

Simple Sugars

• Foods high in simple sugars including soft drinks, undiluted apple juice, Jell-O, and presweetened cereals worsen diarrhea through osmotic effects 4, 5
• High glycemic index foods should be avoided, particularly after bariatric surgery 1

Additional Food Triggers

Spicy Foods and Seasonings

• Spices directly irritate the gastrointestinal tract and should be completely avoided during diarrheal episodes 1, 4

High-Fiber Foods (Insoluble Fiber)

• Whole-meal or high-fiber flour and breads, bran cereals, whole grains (brown rice), and raw vegetables containing insoluble fiber can worsen symptoms 1
• Important distinction: Soluble fiber (like oats) may help, while insoluble fiber typically worsens diarrhea 1

Gas-Producing Foods

• Cauliflower, legumes, beans, and certain vegetables increase bloating and can worsen diarrhea 1, 4
• Chewing gum should be avoided as it promotes gas production 4

Excess Fresh Fruit

• Limit fresh fruit to 3 portions per day (approximately 80g each), as larger quantities trigger osmotic diarrhea 1

Resistant Starch

• Found in processed or recooked foods, resistant starch resists digestion and reaches the colon intact, worsening diarrhea 1

Supplement-Related Causes

Vitamin and Mineral Supplements

• Calcium and iron supplements commonly cause constipation but can also trigger diarrhea in some patients, particularly after bariatric surgery 4
• Magnesium supplements in high doses have a well-known laxative effect and can cause osmotic diarrhea 4

Bile Acid Sequestrants (Paradoxical Effect)

• While cholestyramine, colestipol, and colesevelam are used to treat bile acid malabsorption-related diarrhea, they can cause diarrhea in patients without bile acid malabsorption 4

Context-Specific Considerations

Post-Bariatric Surgery

• Patients are particularly prone to diarrhea from simple sugars, high-fat foods, and lactose-containing products 4
• Dumping syndrome occurs in 40-76% of RYGB patients when consuming sugar-rich or hyperosmotic foods 4
• Small intestinal bacterial overgrowth (SIBO) is more common after malabsorptive procedures and can cause chronic diarrhea 4

Microscopic Colitis

• Bile acid diarrhea is prevalent in 41% of collagenous colitis and 29% of lymphocytic colitis patients 4

Cancer Treatment

• During chemotherapy, milk and dairy products (except yogurt and firm cheeses) should be avoided, along with reduced insoluble fiber intake 4, 1

Critical Pitfalls to Avoid

• Do not assume all fiber is beneficial – insoluble fiber worsens symptoms while soluble fiber may help 1
• Do not overlook contaminated water sources – lakes, rivers, and inadequately boiled water during boil-water advisories can cause infectious diarrhea 1
• Do not ignore cross-contamination from raw eggs, undercooked poultry/meat/seafood, unpasteurized dairy, and unwashed produce 1
• Do not dilute infant formula or delay full-strength feeding, as this worsens nutritional outcomes and prolongs diarrhea 5