History, general examination of patient abdomen followed by ultrasound (if not trained sonographer then get it done through radiology dept) 

One should be using the standard of medical examination:  inspection, auscultation, percussion and palpation. Unfortunately, many young doctors tend to forget about these basics and tend to use medical diagnostic tools and laboratory results initially, before physical examination.

The order of approach to a patient :

Complaint, history of the disease, personal and family history of major diseases, including the medicines used and allergies, past surgical history etc, .

Then the vitals are recorded, fever, blood pressure, ventilation,  cooperation and orientation of the patient is noted.

then comes the physical examination as previously described.  Then the supporting diagnosics or laboratory tests are requested.

https://www.amazon.com/Textbook-Physical-Diagnosis-History-Examination/dp/0323221483