Green loose stools, weight loss, just came back from south asia vacation ?

Need tests: This requires a doctor's visit to review your symptoms and, at a minimum, submit stool tests and possibly blood and urine tests. The most common causes of Traveler's Diarrhea are bacteria, but parasites including giardia are also relatively common. Don't just take Pepto-Bismal; go in so an accurate diagnosis can be made and you receive the correct treatment. Good wishes:)

Vacation: I think you should see your doctor fairly soon. If the delay is too long please go to the nearest Emergency Room for evaluation.