Do I have a parasite/intestinal worms?

What you saw in your stool may simply be partially digested fibres from something you ate. Pineapple and other fruits or vegetables are often passed partially digested and may be observable in the stool as string-like objects, especially if they're the same colour as the stool. Parasites may only occasionally, or even rarely, be observed in stool depending on what type a person is infected with and the severity. When observed in the stool, a parasite is usually a bright white or pinkish colour and isn't likely be confused with partially digested food. A tapeworm infection may be observed as translucent/bright whitish segments in the stool that may resemble large rice grains. In any case, if you discuss this with your doctor you will need to be more detailed in telling him/her what you saw.

Have you had any anal itching...? If you do I've heard you can put tape when you sleep, because the worm comes out at night when you are warm in bed and lays her eggs. But you have to wake up and check to see if you caught the worm. If you do not have anal itching you might want to see a doctor, see if you can request a stool sample. In the meantime make sure you are washing your hands very well, especially under your nails. If you live with others and prepare foods for them, they may need to be checked also.

You can get this from eating out anywhere, somebody may have touched or prepared your food and not washed their hands well enough and you may have gotten a worm egg in your food.