if it starts to ooze white or green stuff you need to see an infectious disease MD. They specialize in hard to heal wounds & will do a culture to make sure no infections are hindering it from closing up.
I had surgery back on 6/20/13 and the wound didn't close. It started to drain green stuff so she cultured it and it came back positive for Staph infection. I was on antibiotics for 2 weeks.
Then after than, it still wasn't closed, so another culture and this time I was positive for 2 infections, Staph and E. coli as it's right near my stoma. And again, I was on antibiotics but the darn thing is spitting out bits and pieces of internal sutures that were suppose to be dissolved within my body. So, I had more blood work done and I'll get the results next week. it's the size of 2 pencil erasers but it needs to close so I don't get anymore infections.
Seeing as it's getting bigger, something's brewing. Get in to see the infection disease MD. Better safe than sorry and he can tell you what's going on with your body.
good luck.