Hello I have gone through your question and understand your concern. The symptoms of abdominal pain and stool culture showing pus cells along with Giardia cyst is suggestive of Giardiasis. Giardia Lambia is a parastite just like intestinal worms, it trasmited by feco-oral route through human fecal contaminated water, food, oral-anal sex. The symptoms of abdominal discomfort, fatty, foul-smelling diarrhea and malabsorption of nutrients experienced once the parasite lodges the human intestine. Kindly, visit a doctor with your stool culture reports as Giardiasis need treatment with antibiotic like metronidazole and is not self limiting like most viral diarrhea seen often.