You need one heck of a better explanation from your doctor. Go back to your doc and get a valid explanation. Unless you misheard or misunderstood what he said, 'knot' - in the way in which you wrote it - means nothing at all.
Hi.. My son's doc said the exact same thing.. I know this is a very old topic but if u can let me know what did the doc say abt ur kido and what was the medication/ next steps to get this health issue sorted.. I will be very thankful for ur response.. Looking forward to hearing