I became intolerant to soya for a few months after taking antibiotics. I had violent diarrhoea and stomach cramps. It is a common allergen and you will see it listed as such on food labels. I think reactions vary from people to people.
There is big difference between allergies and intolerances. Intolerances can make you feel very ill, often a while after being consumed, which makes them difficult to identify. Allergies like the peanut allergy are far more serious, often life threatening and the reaction more instant, often involving the swelling of breathing tubes.
There are various ways to find out if you have an intolerance to soya. There various expensive allergy tests, which have debatable results. I found out as a by-product of other tests I had while seeing a nutritionist. Huge relief and I was able to reintroduce soya back into my diet after a year of avoidance. The other test I have faith in is called a kinesis (I think) test. You put a food in your mouth, then try push the practitioner's hand up. If you are intolerant, you can't push their hand up. Really, really weird, but it worked. My chiropractor did this test for me.
I hope this helps.