Many filarial infections (infestations) show no positive stool test. Often stool test are done to look for ovi (eggs) although frequently filarial infections (infestations) show no positive signs of ovi even when there is a definite parasitical infection (infestation).
The above image is definitely similar to many filarial infestations although I am not sure what type of worm this is.
Frequently what we believe to be just diarrhea is, in fact, large worms that have died off or broken free and passed in the stool. This is often caused by eating something that a worm disagrees with or a bacterial or viral infection that kills off the worm (or weakens it) causing it to release and pass in the stool with the appearance of what we call diarrhea.View Thread
I know this is a fairly old post (3 years ago) although I wanted to see if you are still getting notifications for any replies. I recently passed an almost identical looking stool and wanted to know if you found out anything. How are you now? Any other related symptoms or has your doctor given you any answers?