cause for the diarrhea is unknown ,can some one share if they had experienced the same or what it could be??? pl help...

Hi ,

My husband had loose green watery stools on feb 26th  for  6 to 7 times. 26th evening we went to the doctor.. he gave us some medicines... we came back home... the diarrhea did not stop so  he was admitted the next day . diarrhea did not stop but he was sent home with some medicines.. we were there at home for a day, no improvement so went to another hospital and got admitted . his blood test , stool test , culture test all say normal, colonoscopy was done but said some ileo colonic ulcers.. biopsy just showed some inflammation of cells .. he was admitted for 2 weeks .. finally diarrhea came down to 2 to 3 times a day . he was sent home with ciploid and vanlid 500 mg.... he had them for a week, his stools turned brown and was normal.. we were happy ... he was okay for just about ten days ... on march Friday 28th ... he came home with fever 99 degree Celsius.. and had loose motion (similar to  baby's stools) . fever continued on Saturday. Sunday it is fever with green watery diarrhea . back to square one... he has diarrhea for 8 to 9 times a day. colonoscopy was done again , it showed infective ulcers through out the colon, sample is sent for biopsy again.. .. fever is fluctuating... when he takes dolo 650 mg, fever comes down, then after few hours fever is shown again. i am very very very worried.. blood test says its normal.. what is it? why is the cause for diarrhea still unknown??? is it typhoid turned this way or is it enteritis or viral fever or what is it???? It's been a month now... have Any doctors or experts in investigation of diarrhea have come across such cases???  Please do not give silly answers... I am really really worried...