Using Arduino to read Data from ADS1113
What do you mean about 4bytes.
Your code is correct and received all requested 4 bytes 1 by 1 

this loop run four times and received all data from the I2c Slave.

 while(Wire.available()){    



    float RAW = Wire.read();  &lt;&lt;--------------- at this line 
    float RAW_voltage = (RAW*4.096/32768.0);
    Serial.print("Raw ADC value = ");
    Serial.print(RAW);
    Serial.print("\tVoltage = ");
    Serial.print(RAW_voltage);
    Serial.println();
  }


But if your ADC values are not changed that means your sensor ADS1113 not configure/working correctly first of all check your sensor output.