How to find IBS trigger foods with a food diary

What to record

Food alone is only half the picture. Log symptoms, bowel movements and context so you have something to compare.

• Food and drinks: the dish name, rough portion and the time you ate
• Symptoms: bloating, pain, gas, diarrhea, constipation, with intensity 0–10 and start time
• Bowel movements: Bristol stool type (1–7) and urgency
• Medication, supplements, menstrual cycle, stress and sleep

How to read the pattern: time window and counts

IBS symptoms often start hours after a meal, not right away. So for each symptom, gather the foods you ate in roughly the 6 hours before it and count how often each one repeats.

If you had bloating 9 times and milk came before it 7 of those times, milk is worth testing. But a staple like rice will appear before every symptom, so for foods you eat daily also check how often a symptom followed on the days you ate it.

Common mistakes

• Cutting a food after one bad day — wait until it repeats at least 2 or 3 times.
• Logging from memory at night — wrong times break the time-window analysis.
• Removing several foods at once — you will not know which change helped.
• Avoiding suspects forever — plan a reintroduction with a dietitian, for example as part of a low FODMAP diet.

Log it with Bellywise

Bellywise is a free IBS food and symptom diary with no account. Pick a symptom and it ranks the foods you ate in the 6 hours before it with real counts, like "before bloating 7 of 9 times", over 7, 30 or 90 days.

Medical note

This guide is general information, not a medical diagnosis or treatment. See a doctor promptly if you notice blood in your stool, unintended weight loss, pain that wakes you at night, fever, or a new change in bowel habits after age 50.