According to wikipedia.org, Isaw is a street food from the Philippines, made from barbecued pig or chicken intestines. The intestines are cleaned, turned inside out, and cleaned again, repeating the process several times; they are then either boiled, then grilled, or immediately grilled on sticks. They are usually dipped in vinegar or sukang pinakurat (vinegar with onions, peppers, and other spices). They are usually sold by vendors on street corners during the afternoons.
Thank you,
Grazey Jhud