Found in boys potty. Worms?

https://www.curezone.org/ig/i.asp?i=112681

https://www.curezone.org/ig/i.asp?i=112682



Found this in my 3 year old son’s potty after he went to pee and then said he farted. This is the 5 th time something like this has happened in the last 6 months. He also has a teeny little bulge beside his belly button that we are wondering if it is a hernia or worms.

We took a sample to the Dr and had a parasite ova stool test done with no results. Please help us identify this.

Thank you