Notice whether you get symptoms after eating or drinking dairy
Watch for bloating
Watch for gas
Watch for stomach cramps
Watch for diarrhea
Watch for nausea
Check whether symptoms start within 30 minutes to 2 hours after dairy
See whether symptoms happen more after milk, ice cream, or soft cheeses
Try avoiding dairy for a few days and see if symptoms improve
Try reintroducing dairy and see if symptoms return
Compare reactions to lactose-free milk versus regular milk
Ask a doctor about a hydrogen breath test
Ask a doctor about a lactose tolerance test
Ask a doctor about a stool acidity test if needed
Seek medical advice if symptoms are severe or frequent