Backpain when cough

Patient: Im done with my 5 days medicine intake of broncaire exp and azythromycin which my doctor gave due to my excessive cough with phlegm.. After 5 days i have experiencing loose bowels or diarrhea and pain in my left breast bone and left back.. Other than everything is normal.. What should it be..

Symptoms: Mild coughing with dark green phlegm; back pain everytime i cough and move.. Watery bowel after eating.