Hi Doctor, Please Help Me: (" Please My Son Age

Hi Doctor, Please help me: (" please my son age is 2 year 4 month, his stool is some time loose and sometime normal. But sometime come fever(102-104 degree Fahrenheit) when stool become very loose (watery), it continue 4-6 time in a day for 1-2 days then it become normal. Last 2 month it continued 3-4 times. We tested his stool in Laboratory and findings are : Blood-Absent, Mucus-Trace, Worm-Absent, pH-Acidic, Puss Cells-1-5, Protozoa/HPF/Helminth/LPF/RBC/Macrophage-Absent". His weight 12.5 KG now, his health is declining)