Why is my stool mushy and smelly and changes colour all the time and it has been nearly a year now?

Mushy,smelly,color : In my experience,smelly stools don't provide any diagnostic help. However, high fat foods can make stools yellowish, soft and foul smelling. White,clay colored stool may be a sign of failure of liver to release bile salts into fecal matter in the intestines or bile blockage.Black stool is a sign of upper gi tract bleeding. Green stool means feces moving too fast through the gi tract to turn Brown.