'Had the same thing a while back. I was worried as they sent me to hospital for consultation followed by a prostate examination!
That produced nothing so 2 more trips to hospital culminating in the endoscope being shoved where nothing should go!!!
They tell you it won't hurt...it fecking did! Then they told me that if they had advised that it would it would have left. They were right.
Anyway, I saw the live pictures myself with the doctor and there was nothing. Nothing at all.
Since then get renewed each year with no dramas so I would suggest that although it can be indicative of a problem, it generally is not. They just like to make sure thats all.