What Causes Tissue Blockage In The Navel Region?

Hello, I have noticed that some tissue is protruding from the wall of my belly button. It seems to fill about a quarter of the belly button itself. I experience periodical pain or discomfort in my large intestine, particularly descending colon region. Nothing too intense, but the pain varies. I just noticed the bulge in the belly button a few days ago. It is not painful, just feels like soft tissue. Thank you for your time.