Can a hernia be missed on CT scan if it's small?

There are many types of hernias which you named a few all of which are unrelated and have different causes and treatment.  Have a meeting with your general surgeon to dos us your symptoms and address your concerns. 

I don't entirely understand type of hernia you are concerned about. It is clear that you have an umbilical hernia. It is clear that you have a diet stasis that has fortunately been reducing in size. If you're concerned about hiatal / esophageal hernia, CT scan can sometimes show it, though not always. In general the most accurate diagnosis will be made through endoscopy or other G.I. evaluation Area I recommend you seek that type of advice if you're concerned for it. I wish you the best. Dr. Gabbay.

Most CT scans have a resolution of about a cm. Very small defects could be missed or through signal averaging not read as a hernia. Your surgeon will be able to tell at surgery if a true defect is present. Good luck.

Hi, Steph5432.  If a hernia is very small, it can be missed by CT scan.  However, hiatal hernia or esophageal hernia is more of functional problem; it may not be detected on CT scan.  If you have chest pain or reflux due to hiatal hernia/esophageal hernia, you need to consult a GI physician.  Best regards.