The causes of various types of intestinal obstruction are as follows: (1) Mechanical intestinal obstruction: (1) External factors: ①Compression by adhesions and adhesion bands. Adhesions can cause intestinal folding and torsion, leading to obstruction. Congenital adhesion bands are more common in children, while adhesions caused by abdominal surgery and peritoneal inflammation are more common in adults. ②Strangulated external hernias or internal hernias. ③Compression by extraintestinal tumors or abdominal masses. ④Intestinal volvulus, often caused by adhesions.