DBLC, I was infected by contaminated food. I had symptoms within a couple of weeks, but thanks to the medical system it went undiagnosed for almost a year and a half. I had suspected it, but didn't know that tests are almost always negative.
The times I have seen worms come out have with an enema so it was just water and worms in the toilet. yum, right?!
It's sad that in more 'civilized' countries they don't recognize that parasites are a problem. They tell you that you have to be very dirty or have traveled to a foreign country. It's just not true. They are everywhere,and will settle in a low acid, highly stressed body.