Stumped

1992 went to Costa Rica, spent 1 month, got sick on the last day with diarrhea every 10 to 15 min.  Got home and was sick for 2weeks, took Ceclor and got better.  Went back every summer for 2 months and got sick each time.  It's now Nov. 1, 2001 and have had diarrhea every 5 to 7 days with really loose stools ( 4-6 times a day) for the last month and a half.  Just sent my first stool sample in to check for ova and parasites and giardia.  Also got sick on cider about 5yrs. ago (I know because my husband did too) and never took anything.  Thought it might be giardia.  I'm just tired of eating and having to evacuate 20 to 30min. after.  It's getting to be life altering having mild cramping and having to constantly be aware of where a clean bathroom is so much so that I don't want to leave the house.  Anyone out there?