My stool is soft, formed, and brown, however, there are little white seed like pieces, rice like pieces, and small white chunks. o/p was negative. ?

Oxalate?: Have you been on any antibiotics or anti-fungal agents? Sometimes when you are treating one infection, other organisms will over-grow and result in specks or "grains of rice" in the stool. As they are crystals or fungal elements, they will not be positive with an o ; p study. Good luck.

Undigested food: You may be seeing pieces of undigested food. If you have no abdominal symptoms, please do not worry about it.