What Causes A Lump Beside The Navel Region Along With Vomiting?

I have a gastric band which has no fluid in it right now. It has been in place for 5 years. This am, sudden onset ,severe vomiting, which had subsided. I now have a knot/ hardened area ( baseball sized) on my left side right next to my navel. Eating or drinking anything causes vomiting within 30 min. Painfull to liedown on either side. No pain as long as I sit up