Hello doctor. i am a male. i think a sperm just went to my anus. what will happen to the sperm, will it meet threadworm and it eggs and fertilize it and i will die or what. please explain, thank you?

If sperm enter the anus, they will just die off relatively quickly. The environment is not favorable for survival and nothing in there they can fertilize, including threadworm eggs. Sperm can only fertilize a human egg.

Your sperms died and totally disintegrated in less than 10 mts after ejaculation and will come out with the next BM. None of the things you worry about and you will live a long and healthy life. Pl do not overthink things.

What you described will not harm you even one iota. For healthy diet: http://www.choosemyplate.gov/., exercise 30 minutes/day, drink enough water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs. Get HPV vaccine. Wish you good health! Safe sex: https://www.hopkinsmedicine.org/health/wellness-and-prevention/safer-sex-guidelines