<prompt> The most common cause of small intestinal obstruction is:IntussusceptionIatrogenic adhesionTraumaCarcinoma  <response>: Adhesion secondary to previous surgery are by far the most common cause for small bowel obstruction. Adhesions paicularly after pelvic surgery are responsible for more than 60 of cause of small bowel obstruction. Causes of small bowel obstruction in order of frequency: Adhesions Approximately 60 commonest Malignant tumors approximately 20 second most common cause. Most commonly these tumors are metastatic lesions. Hernias Approximately 10 Crohns disease approximately 5 Ref: Sabiston 18e, Page 1290. 