Chronic Diarrhea

Eight months ago I tested positive for a parasite Giardia with many cyst. After 3 rounds of antibiotics my symptoms still did not go away. I was then given a colonoscopy and a Barium x ray. The results were that everything was normal and I was told to just take anti-diarrhea medication. Now, eight months later I am still experiencing my symptoms. Which include: nausea, vomiting, bloating, stomach cramps & loud noises, fatigue and diarrhea. I have had a CBC and it only showed low potassium. I am at my wits end here. It is effecting the time I spend with my two year old, my job, and now my social life. Any suggestions as to what could be causing these problems please let me know. Thank you.