Hi Doctor! My Baby 16 Month Was Diagnosed With E-Coli

Hi doctor! My baby 16 month was diagnosed with E-Coli last month , doctor suggested for Stool RM and Cultural test, He has been administered Wallamycin syrup for last 20days. Today the latest report says the Reducing substance- Trace and occult Blood test- negative, please tell us is everything in order or I need to reffer to another doctor for further treatment or guidance. Though my baby is doing well eating well and weight is also normal.