What is a white stringy mucous looking thing found in a stool.... is a doctor needed?

Mucus with stool. Mucus discharge occurs in up to 50% of patients with irritable bowel syndrome, with or without pain. Mucus may also be produced in response to partial obstruction, chronic constipation, rectal dysfunction, infection, & even from secretory villous tumors of the rectum. At the very least stool studies & probably a sigmoidoscopy should be considered, but a more extensive evaluation may be warranted.