Respected user, hi I evaluated your query thoroughly.
*Only discomfort with milk & spicy food don`t stamp you to have IBS.
*Relate it as IBS coming back , if you were previously documented to be 
  suffering from IBS ( with 
lactose intolerance )
*I suggest you following to make things better :
- Avoid all oily / spicy / nonveg stuffs / beverages / excess ghee / cheese / 
  sugars / artificial sweeteners
- have light diet, plenty of liquids preferably boiled water, boiled milk, 
  coconut water, green tea, coffee, butter milk etc. 
- have small amount of food at definite intervals
- fix timing of breakfast, lunch , dinner
- chew your food very thoroughly.
- avoid 
smoking / alcohol / any abuse substances if used in any form
- avoid prolong fasting / overeating
- avoid sleeping for at least 2 hours after lunch / dinner
- have adequate sound sleep of 8 hours
- avoid 
stress / anxiety
- keep your BP , Weight ,  Blood sugar , 
Cholesterol levels in control
- In our clinic after clinical evaluations in certain cases we prescribe Pre-
  probiotics containing 
Lactobacillus ; 
Proton pump inhibitors for faster 
  recovery 
- do regular walking in fresh air to rejuvenate body with fresh oxygen
- do regular deep breathing exercises, 
YOGA with some light exercises 
 Hope this clears your query.
 Thanks for using Health care magic & keeping trust in our medical services
 Wishing you fast and speedy recovery from the same.
 Regards dear take care.