Aiyoh, I'm so sorry lah, stomach cramps are real, not just in your head! A few of us mums in my circle also kena like this, and people at work memang tak paham je. Allergies affect your gut lining and how your body processes food, it's actual physical thing, bukan imaginary. If your perut keeps cramping, maybe tanya doctor to identify exactly what's triggering it so you can avoid or manage better, then at least you boleh explain to your colleagues with proper medical backing, because honestly some people only believe when got doctor's note haha! Take care of yourself ya, and don't let their comments make you feel guilty for something your body genuinely can't tahan.