Hi. Thanks for your query. Noted the history of a differential diagnosis put on the paper you have submitted stating nonspecific abdominal pain, cholecystitis, gastritis, gastroenteritis and viral infection. Differential diagnosis is given by a Doctor on clinical basis, examination and gives an Idea about what investigations are needed. I hope this answers your basic query. You should undergo the following: Ultrasonography followed by CT scan to know the Exact diagnosis. Tests of Stool, blood and urine in addition will give us further diagnosis. lPlease get all these things done so that you get a definite diagnosis and proper management.