I Have Had Diarrhea Going On 4 Weeks... I Was

I have had diarrhea going on 4 weeks... I was told OTC Immodium would not help... I was told to have a stool sample made and it came back negative... then last night I developed a 102 temp with light chills... my husband called my MD who was on call & he told my husband to give me tylenol and immodium and if I was better by today to come in... of course this is Friday... my fever broke but my diarrhea did not subside until now but this has happened before i.e., I thought I was better then the diarrhea would come back... any suggestions?