Chicken Tikka Sub Reaction - Subway, Northern Ireland

Royal Avenue, BT1 1DD Northern Ireland, United Kingdom

Eating a chicken tikka sub with lite mayo and lettuce and tomato It just kicked in around 6 hours after and it’s the only other food we ate today. My husband is fine but he got different ingredients so I suspect if it was there it was the chicken tikka, salad or the mayonnaise. Also got a minimal amount of sea water in my mouth as it splashed up from rocks. But seems more likely to be from here the subway as it started around 6 hours after eating.
UPDATE I received a friendly, professional and concerned response from them. Tried to reply to email with detailed response and answer all of the questions but it just goes to draft and won’t send.
UPDATE response seems to have finally sent. | Symptoms: Diarrhea, Nausea