Yeah, don't go after the flagellates unless you actually know they're there. Fasting and weight loss are normal this time of year. And lime green poops are actually urates.
(To date I've had to treat three snakes for flagellates: two in early 2009, one in early 2010. It does involve a month or two of rebounding as the digestive tract recovers, and my 2nd pied spent several extra months producing The World's Smelliest Poops. But everyone recovered their appetites within a couple weeks of the first treatment.)
Yeah see, I know about flagyl, i'm a vet tech but for dogs and cats! I really don't know much by the snakes. She gave me this small like dime size light lime green squiggly poop then 2 days later this huge poop and that was that. I've never seen it again.