️ The three that can make it worse

Stress is not the only cause of IBS, but it can trigger flares in people who already have it. The gut-brain connection means psychological stress directly affects gut motility and pain sensitivity, which is why IBS symptoms often worsen during stressful periods. The relationship runs both ways. Gut symptoms cause stress and anxiety, and stress makes gut symptoms worse, which is why IBS often feels like a cycle that's hard to break.

Post-infectious — the pattern that shifted everything

Some people develop IBS specifically after a gut infection, which suggests the disruption that happens during acute illness can sometimes trigger lasting changes in gut function. Post-infectious IBS is a recognized clinical pattern, documented as a subset of IBS cases following acute gastroenteritis. Changes in gut bacteria are commonly reported in IBS research, though it's not clear whether those changes cause IBS or result from it. The relationship is likely bidirectional, and SIBO — where bac

One number that doesn't move

Many people with IBS use a low-FODMAP process to identify specific foods that trigger their flares. Keeping a symptom diary before making dietary changes gives you actual data on your triggers, not guesswork. Onions and garlic are common high-FODMAP foods. Garlic- or onion-infused oil is commonly used in low-FODMAP cooking because fructans are not soluble in oil — the flavor transfers without the fructans. Women are more commonly diagnosed with IBS than men. The gut-brain axis is now central to

Foodbe

June 4, 2026

What causes IBS?

The cramping starts an hour after eating — not during, when help might actually be possible. That kind of delayed cramping can fit with IBS, where gut-brain communication problems appear in many patients.

IBS doesn't have one single cause. It's a syndrome with several overlapping drivers: gut-brain communication problems, heightened gut sensitivity, changes in gut bacteria, and a history of gut infections or chronic stress.

IBS usually does not have clear structural abnormalities on routine diagnostic testing. The gut and brain are in constant communication through the gut-brain axis, and in IBS that signaling appears dysregulated, which may make normal digestive activity feel painful or urgent.

People with IBS often have a more sensitive gut than normal. Research suggests visceral hypersensitivity — a lower pain threshold in the gut — is one of the most consistent findings in IBS studies, meaning the nervous system that controls the gut becomes more sensitive to normal digestive signals in a way that causes pain or urgency.

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Foodbe.ai exists to inform consumers about the food they buy and eat. Every claim is cited. Sources: NIH, USDA, FDA, Smithsonian, and JSTOR. Found an error? Email us at admin@foodbe.ai to report any source or fact issues.