Alamak, obimin memang kenal lah boleh cause stomach upset kat beberapa orang, iron supplements tend to do that! A few of my mum friends complained about this jugak, especially kalau take on empty stomach. Try makan lepas makan proper meal, or maybe switch timing to before tidur malam instead, and tengok kalau better. If the cirit birit terus jalan, mesti check with your doctor lah because maybe perut you need different type of iron supplement or dosage adjustment, especially if pregnant or breastfeeding.