You will probably see signs for various types of bún măng in Vietnam. It's a vermicelli noodle soup with chunks of bamboo shoots in it. The bamboo shoots are a bit of an aquired taste. They come dried, not fresh. This means they are soft, not crispy. There is a bit of a funky stink to them, but in the soup they aren't as strong. I'm not a fan of bamboo shoots that come in a can. They are the fresh kind, which I find too pungent, but the dried bamboo in Vietnamese soup I enjoy. The soup will come with a meat (unless it's vegetarian) -- the most popular being duck or chicken, and all parts of the animal may be present (kidney, liver, congealed blood, etc).
Types of bun mang
Bun Mang Vit/Duck and Bamboo Noodle Soup
Bun Mang Ga/Chicken and Bamboo Noodle Soup