2 years back I was having diarrhoea after having dinner in a restaurant and it continued with loose stools for almost months, All the test came negative along with Endoscopy and Biopsy and In allergy panel milk and milk products was showing moderately positive and Egg as weak positively other all food ingredients were negative. I stopped having milk from that point of time as per my doctor advice. He told me to give a trial and error method of trying the same product after sometime to check whether it is allergic but I never tried to avoid any further issues. I was having weight loss around 5 to 6 kg. Now my stool problems are almost back to normal. Still if I have ice creams the next day some stools are a bit loose. my question is can all of a sudden milk allergy happen because I had the same milk for the past 28 years no allergy was there or can I try having milk again. I still consume curd, butter milk on daily basis. Is there any particular test to check milk allergy or intolerance