Im 40 yo male. had d for 3 mo on and off. blood and colonoscopy came back ok. still tested pos for c. diff colitis. no fever either. im in day 6. on flagyl. i have cramps after eating and fluffy loose stool. is this something to be concerned?

Only a little: C. difficile is always something to be "concerned" about. But you are experiencing a rather mild case, and the Flagyl probably will take care of it. Cramps and loose stool could be due to C diff (symptoms often improve slowly) or the Flagyl. Complete treatment as prescribed and contact your doctor if symptoms continue. My guess your doc may have already scheduled a follow-up appointment.