It also depends on what the foods actually are that are affecting you. You may not be lactose intolerant, you may just be intolerant of the substance containing the lactose. For example, I can eat cheese all day long, always have, always will, and will die before I am forced to stop; but you give me a milk shake, heck even yogurt, anything in a liquidish form; an hour later I'm in the bathroom, cheese dip seems to do the same. So mine seems to be more related to the weight of the item, and those few items are pretty heavy on your stomach.
However, I am on some new meds, some 10mg anti-depressants, supposed to affect the serotonin in your body, I do not seem to see a lot of difference most of the time, however, I have noticed a slight calming of the nerves, and last night I had a milkshake and had no adverse results, so who knows.