Often, anything yellow in feces is bile.
This question is a FAQ on this forum, and this answer is my FAA on that question.
My Friendly Suggestion: Feces Diagnostics
To all of you who are asking the question about feces.
If you are serious about trying to identify anything in your feces, you will really have to do a proper job, to have any chance of findING what it really is.
Separate objects, worms or whatever else is of your interest from the feces.
Wash it with clean water.
You can use rubber gloves.
Place it on a clean paper plate or something similar.
Take a high resolution photo under a good light.
Best use daylight to get correct colors on the photo.
Than publish the photo and ask the questions.