A 3-year-old child has been suffering from persistent cough and was diagnosed with lung infection after hospital examination. The child has taken Qingxuan Qingfei Granules, Jinfeng Granules, Ceftizoxime Granules, and Qingfei Liquid, along with two white tablets. After one and a half days of medication, the cough persists, and this morning, diarrhea with bubbles appeared. Past treatment and effects: The cough continues without improvement. A chest X-ray confirmed lung infection, and the child has been taking the aforementioned medications as instructed by the doctor. Current condition: The child still has a cough after taking the medication, and diarrhea with bubbles appeared this morning. What help is needed: Should the cough medicine still be taken when the child has diarrhea? Is it necessary to take additional medication?