It is true that most distilled water contains contaminants or pollutants in very small amounts both from the water source but also from the equipment and plastic bottles. These contaminants sometimes stay in the body and build up over time and can cause ill health. But I have also talked to quite a few people who thought the water was causing their problems and it turned out that water was not the cause, usually they had some underlying health problem that was getting worse.

I think that a good course would be to have a check up with a DR. and look at the programs for improving health at the Liver Flush Support Forum .

If you would describe the problems you are having we might be able to direct you to some of the appropriate forums.

I am doing it for 7 years. No side effects. My friend, who has stomach weakness/high acidity/probably gastritis if not ulcer, claims that she felt pain the first few times she got it at my place. Then after, she was miraculously OK with drinking it. I believe if there is acute gastritis/ulcer, meaning a spot in the stomach not well protected by the natural gastric mucoid substance, it can lead to pain through directly swelling up the gastric cells at that spot. It is theory of mine.
Also, when having distilled water on a daily basis for months and more, you need, of course, to make sure you are getting minerals from you food. "Regular" food, is not best. You need lots of vegetables, fruits and or vegetable juices. Western diet can make you deficient in calcium, for example, even if you have dairy, because the acidity of the dairy, and grains, and meat ... everything except veggie and fruit, is to be neutralize by calcium, usually drawn from bones and teeth (and then lost in the toilet), because we hardly absorb casein-bound calcium.