I had patella bursitis last year i got it 3 weeks before i was due to do my first marathon... :0 (
It took a good 4/5 months for it to go as for some odd reason it started to solidify as it was going down.
I was told not to run and just cross train making sure i put ice on it and take anti inflammatory and it will go in its own time... (not what i wanted to hear)
Not a happy thought is that once you have had it once you are more prone to get them apperently...
On the upside they do go and it gets better!