What's the standard treatment of post op adhesions which causes obstruction in the small intestines after a sigmoid colon cancer surgery?

Each person is: Different, no true standard. First would be identification if true obstruction, partial or complete obstruction. Often initial treatment is IV fluid hydration & medication for pain & nausea. Serial physical exam & abdominal x-ray. If complete or unresolving obstruction, then surgery is performed to remove adhesions. Pain by itself is not an obstruction, unrelenting vomiting & no bowel movement is.

None: There is no rx for adhesions themselves. If they cause a bowel obstruction then that will be treated with a tube through the nose to decompress the bowel and no food for a few days. If that doesnt work then surgery may be required.