How does surgery for stage 1 rectal cancer work?

Through abdomen/anus: This is where the cancer does not go past the muscle layer. Surgery can cure this but there are risks. Surgery can be through the abdomen with or without surgery on the anus. The first way might need a temporary or permanent colostomy, an opening for expulsion of waste. The other way requires a permanent colostomy. Surgery may be done that just involves the anus, but that risks recurrence.

Removal of the tumor: If the rectal cancer is very small and near the anus, some specialized surgeons can remove the tumor through the anus with special instruments - this is unusual to do. Most will use open or laparoscopic surgery to remove the piece of colon containing the tumor and reconnect the colon to itself using stitches or staples. If the tumor is too close to the sphincter it may not be reconnected.