Loose motions with fever since 3 days.

Dear sir, My son is 09 months old & suffering loose motions with fever since 3 days ( first day loose  motions and second day onwards fever)  Today we went to hospital and the paediatrician suggested for ORS ,Enterogermina , Zinc Acetate Oral solution and P-125 drops. But he did not even check the temperature and told me that it is nothing and not to worry. But my son is suffering everyday fever also. Heat is particularly at head part and it is increasing on nights. Day times the temperature is not so high. His motion is FULLY IN YELLOW COLOUR AND GREEN WATER LIKE. We are so worried though we use medicine. Today we start the medicine except P 125. Till yesterday we were using P125.My worry is that WHY IT IS NOT GETTING CURED EVEN AFTER THE MEDICATION ALSO. My doubt is, are the  medicines above said are really usefull. Or do we need to go for further medical examination for my son Or shall I wait for two more days by using these medicines. Pls suggest us sir. We are really worried.