It is usually made from the intestines of pigs or other animals and can be eaten.

Animal products made by scraping the large and small intestines of livestock. It is mainly used as a coating for stuffed sausages and enema; sheep casings can also be made into gut string, which is used to make tennis racket strings, bow strings and surgical sutures. Casings are divided into pig casings, sheep casings and cattle casings according to livestock. According to the parts, they are divided into large casings and small casings. The intestine is divided into 4 layers from the inside out: mucosa, submucosa, muscularis and serosa. According to the different requirements of animal types and processed products, the processing of the upper four layers is also different. Good quality casings should be tough and translucent. What is emerging now is collagen edible casings.