Roundworms (nematodes) have elongated, bilaterally long cylindrical bodies which contain an intestinal system and a large body cavity. Parasitic nematodes vary in length from several millimetres to approximately 2 metres and have larval stages and adult worms of both sexes. Approximately 60 species of roundworms are parasites of humans.1
This is a companion discussion topic for the original article at https://patient.info/doctor/gastroenterology/nematodes-roundworms