Yes, I would agree staying away from bread is probably wise. Modern wheat is a toxic poison that shouldn't be consumed by humans. Anything with yeast in it will tend to ferment more in the intestines. Rice, oats and quinoa seem pretty safe, amaranth is also very good but the taste may not be for everyone, very nutritious though. If you eat fruit it should be eaten alone not combined with anything this will decrease fermentation in the gut. Some fruits will ferment more than others, see what you feel okay with. I find it strange that you have symptoms of lactose intolerance from yogurt, as the bacteria in the yogurt actually breaks down and digests the lactose so there is very little lactose if any by the time you consume it. You could be feeling a reaction of the probiotics themselves, some people can have problems with fermented foods.