Food & FODMAP tolerance database
Understand how specific foods interact with your digestive tract. Check Monash University FODMAP thresholds, digestion lag timelines, and gentle alternatives.
Garlic
Primary factor: Fructans
Garlic is one of the most potent dietary triggers for IBS. It contains high concentrations of fructans, which are short-chain fructose polymers that human digestive enzymes cannot break down. Fructans pass into the large intestine unabsorbed, where resident bacteria ferment them into hydrogen and methane gas within 6 to 18 hours, causing severe bloating, visceral pain, and altered stool form.
Onion
Primary factor: Fructans
Onions contain dense concentrations of fructo-oligosaccharides. Even small amounts found in commercial broths, sauces, and seasoning rubs are sufficient to trigger colonic gas distension, abdominal cramps, and diarrhea in sensitive individuals 6 to 18 hours after ingestion.
Coffee
Primary factor: Non-FODMAP Irritant
Coffee is technically low FODMAP, but it is a primary physiological gut stimulant. Caffeine and chlorogenic acids stimulate the release of gastrin and cholecystokinin, accelerating gastric acid secretion and triggering the gastrocolic reflex within 30 to 90 minutes. This causes rapid colonic contractions and urgent bowel evacuation regardless of IBS subtype.
Avocado
Primary factor: Sorbitol
Avocado is nutrient-dense but contains sorbitol, a sugar alcohol (polyol). At small portions (30g or 1/8 avocado), it is low FODMAP. At typical culinary servings of 1/2 to a full avocado (80g to 150g), sorbitol exceeds the small intestine's absorption capacity, drawing excess water into the bowel and causing gas and loose stools 4 to 12 hours later.
Oats
Primary factor: GOS
Rolled oats are low FODMAP at standard 1/2 cup portions (52g). However, oats contain beta-glucan soluble fiber and moderate galacto-oligosaccharides (GOS). Consuming large portions (over 75g) or quick oats processed with higher surface area increases fermentation rates, which can trigger bloating and gas in sensitive digestive tracts.
Cow Milk
Primary factor: Lactose
Cow milk contains lactose, a disaccharide sugar requiring the enzyme lactase for breakdown. Approximately 68% of the global population has lactase non-persistence. Without adequate lactase, undigested lactose draws water into the small intestine through osmosis and ferments in the colon, producing watery diarrhea, audible borborygmi (stomach rumbling), and cramps within 1 to 4 hours.
Eggs
Primary factor: Non-FODMAP Irritant
Eggs contain zero carbohydrates and are completely low FODMAP. However, eggs are rich in sulfur-containing amino acids (methionine and cysteine) and dietary lipids. In sensitive individuals, sulfur compounds can produce foul-smelling gas (hydrogen sulfide), while high-fat preparations (such as eggs fried in butter) stimulate cholecystokinin, triggering stomach cramps and gallbladder contractions.
Apples
Primary factor: Fructose
Apples are a double-load FODMAP trigger because they contain both excess free fructose and high sorbitol. Consuming half an apple or more overloads the GLUT-5 transporter in the small intestine. Unabsorbed fructose and sorbitol travel to the colon, where they draw water and ferment, producing severe bloating, gas, and diarrhea 4 to 12 hours later.
Bananas
Primary factor: Fructans
The FODMAP status of a banana changes dramatically as it ripens. Firm, greenish-yellow bananas are low FODMAP and rich in resistant starch, which supports gut lining health. As a banana ripens and develops brown sugar spots, resistant starch converts into fermentable fructans, making ripe bananas a common trigger for bloating and cramps.
Wheat Bread
Primary factor: Fructans
Most people who believe they are sensitive to gluten are actually reacting to fructans in wheat. Commercial white and whole-wheat breads contain high concentrations of fructan oligosaccharides. Consuming regular wheat bread triggers colonic fermentation, gas production, and visceral pain 6 to 18 hours after consumption in non-celiac IBS patients.
Test your personal triggers with GutLog on iOS
Population tables cannot replace personal tracking. GutLog 1.5.6 tests your individual reactions across 6 digestion lag windows using a Poisson arrival baseline model.