An umbilical hernia is a protrusion of fat or intestine beyond a weak spot along the umbilicus and abdominal wall. This is a very common finding I see on the CT scans of the abdomen. They are usually small in size and often are not the primary reason why the patient is getting a CT scan. I also rarely see problems or symptoms associated with this finding, particularly when there is only fat in it. Often times, I do not see them being repaired when small or asymptomatic. This however does not rule out the possibility of future trouble.
When the intestines herniate through this region, then the concern is that the intestine could become injured or squeezed of its blood supply. This is an emergency. You may have pain in the region and your doctor may not be able to reduce the hernia or push it back in. On CT, the hernia will look inflamed and the bowel may not be normal.
In these emergency cases, a surgeon will be consulted and an operation may be needed to prevent complications. The radiologist will alert your doctor to concern about a strangulated hernia and a surgeon will usually be consulted. Although imaging findings are important, they always have to be placed in the appropriate clinical context. Meaning your doctor should never just treat the scan.