thank you for your question... you see burning pain during micturition with loin pain may suggest urinary tract infection...however the same can be experienced due to inappropriate drinking of fluids also...as you have mentioned his hunger was not normal, it might lead to that he was not taking enough water as his appetite was poor... my suggestions will be- drink plenty of water take tab levofloxacin 750 twice daily for 7 days get a morning urine sample tested routine blood count and bilirubin count take multivitamin syrup before food for decreased appetite add enough dietary fibres to the diet get back to be with the reports for further management hope this was helpful... regards