Know the etilogy, pathogenesis, pertinent questions, preferred imaging and treatments for the common intra-abdominal pathology and you'll be fine. ie, diverticulitis, ischemic colitis, Chron's/UC, pancreatitis, appy, gall bladder, liver disease, portal hypertension, ascites, etc. Also have a general idea about various hernias.
Don't worry yourself with the zebras. The vast majority of a general surgeon's time is spent in the abdomen. Make a list and take a day to review each one, especially the preferred workup and imaging, and you'll be ahead of the curve. Be able to answer the basic questions and how each one of these patients would present.
An otherwise healthy, asymptomatic, normal exam 30 y/o male with a hemoglobin of 9.7 is a problem. Where would you go from here?
If you do nothing else, at least understand the common abdominal badness.