I had and still dealing with a severe allergy to Soy Milk and it was good tasting. I had a allergy years ago and mostly hives and rash once and a while. I never drank or ate in large quanities, till now. I had two bowls of cereal and glass before bed. Next day cramps, hives, burning lips, swollen face, legs and feet. I have MS and food reactions trigger relapes for me. I am still dealing with swollen feet 7 days later. On low dose water pill. Hoping it will help. All other areas are back to normal, except feet and ankles. If you have food allergies be aware. Will follow uo with Allergist.
Soy milk can cause allergies in some people and upset the tummy or digestive tract. There are many other poss. it could be but hard to pinn down. I personally drink rice milk as i am lactose intollerant to dairy. Rice milk Takes a little geting used to because it is not as thick as soy and now when i drink soy it tastes like whole milk. If its not working switch off and try something else. Feel better..
I myself cannot tolerate soy milk..... it's the vitamins in it.
With colon sensitivities i have found that staying away from vitamins is best for me... I cannot digest them properly. You should get most of your vitamins from a well balanced diet.
Of course each is different. Do watch your trigger foods. I can tolerate 1% milk and do take a calcium/vit-d tablet..with magnesium everyday. Perhaps you may like to try this yourself.
Best to you.