We are married for 27 years. We often travel and like seafood. After the last trip I felt bad. My stomach ached. The same symptoms were felt by all members of my family.
We all went to the doctor. It turned out we all had a severe gastritis. Gastritis develops from malnutrition and bacteria.
Our whole family changed the diet. We were even shown on TV. The presenter said that she had never seen the whole family fall ill at once.