Why do sunflower seeds give me diarrhea?

Let's define problem: Doctors define constipation as stools less frequently than once every 3-4 days, and diarrhea as greater than 3-4 stools daily. However, food intolerances are common but individualized. Why eat foods that you know will make you sick? Has a seed allergy been evaluated? (Ref. www.livestrong.com/article/449524-diarrhea-from-eating-foods-with-seeds/)