I have never had these flem ball things happen before but I went into surgery last week (a stent was put in my kidney as I had a blockage), when I was bought to my ward I coughed up two relatively small yellowish green coloured balls which looked like hard flem but was also squishy, and the smell was horrific, I have not had any problems with my tonsils, I don't have a sore throat nor do I have any sinuses and since that night I have coughed up 3 more. I can feel them in the back of throat kinda where my glands are. Pleaseee help I don't know what they are? whether the surgery had anything to do with it? and how to get rid of it?