I had this problem last year, after pelvic radiation for UTUC. It got worse no matter what I did. Finally after almost a year, & a clean colonoscopy the gastroenterologist decided to get some stool samples. It turned out that I had E.Coli for at least 5 months. If it continues to get worse, you may want to ask them to do some tests. It could have saved me from a lot of misery. After the E.Coli was treated, I still have bouts of loose stools, just not as frequently. Also, I found that using Metamucil helps to firm & bulk up the stool, as an opposed to Imodium which would flip my symptoms to constipation. Good luck!