Hi, Thanks for posting your query. Kindly mention your whole symptoms in detail. Do you have sore throat/ running nose/ chest pain/ cough with sputum/ loose motion/ vomiting/ spasmodic abdominal pain/ burning urination or increased frequency of urination? Diagnosis of affected symptoms is made on history basis. Antibiotic therapy is decided on the basis of affected system. As you have negative blood culture, there is high chances of viral infection. You have mentioned all investigations, what about your chest x ray finding? If you are suffering from common cold, then you should do gargles and anti-inflammatory, anti-allergic medicines. If you are suffering from acute gastroenteritis, then you should avoid milk and all milk products. You should also take anti-spasmodics, antibiotics, probiotics. If you are suffering from UTI, then you should take antibiotics, anti-spasmodics and search should be made to find the cause of UTI. Take care, Dr. Mayank Bhargava