Primary obstruction may occur due to the physical blockage of the gastrointestinal tract by ingested material such as baling twine, hair or fencing material. Ingestion of objects such as nails, wire or sharp stones may also lead to obstruction via the formation of an enterolith. The most common sites for foreign body obstruction are the small colon and at the junction of the right dorsal and transverse colon (due to the reduction in lumenal diameter at this point). | Primary obstruction may occur due to the physical blockage of the gastrointestinal tract by ingested material such as baling twine, hair or fencing material. Ingestion of objects such as nails, wire or sharp stones may also lead to obstruction via the formation of an enterolith. The most common sites for foreign body obstruction are the small colon and at the junction of the right dorsal and transverse colon (due to the reduction in lumenal diameter at this point). |