How can you tell what food is a trigger

Hi. I have been doing the strict elimination diet for 4 weeks after having problems for the last few years, worsening in the last year. I have definitely seen some relief of symptoms since starting - but some days are worse than others. I have kept a pretty accurate food diary over the last 4 months and I have never been able to see a connection between food and symptoms. I don’t understand how everyone is understanding which things are giving them symptoms and which aren’t. Please help!!