Why does my stool have white mucus it's brown but with white mucus lines it comes and goes i have a really bad diet but i can tell if its mucus?

It may be normal: A little mucus is nothing to worry about if there are no other symptoms.But you should check with your doctor if there is excessive and persistant mucus in stool, or it is accompanied by blood in the stools and if associated with change in bowels.As that may be due to underlying conditions like intestinal infection, inflammatory bowel disease.

Mucus: I don't think this is any significant unless you're having abdominal pain diarrhea or blood in stool.

Other Symptoms?: If you are having any bloating, cramps, diarrhea, or seeing any blood in your stool, the mucus could be relatd to a condition called inflammatory bowel disease. I would visit with your local doctor and have a sit down about the change in your bowel movment you have described and ensure there is nothing to be concerned about.