What Causes Swollen Belly Button With Nausea?

I've had epigatric pain and abdominal distention.had colonoscopy a year ago and was told do not eat raw vegetables.Pain and distention continue. Had hysterectomy eight weeks ago.My abdoman continues to be distended.I noticed a soft protruding bulge that starts at epigastric area and continues toward my umbilicus.I have some occasional trouble swallowing,and nausea,Cat Scan prior to my hysterectomy did not show any fluid in my abdoman.I am wondering should I have endoscopy?