A lower anterior resection is an operation performed to remove part of a diseased colon and reattach the healthy colon tissue to the anus. The resection may require the temporary use of a colostomy bag to collect fecal matter until the colon is healed enough for a bowel movement. It is a less invasive procedure than an abdominoperineal resection, the traditional surgery to treat rectal cancers and some cases of diverticulitis.
Before the lower anterior resection procedure begins, the patient will need to completely empty his colon. A liquid diet usually begins two days before the operation to eliminate any solid material from the colon. The night before the procedure, an enema will be given to remove the last traces of fecal matter. Another enema may be needed the morning of the operation to ensure the colon is free of any trace of feces.
The resection is performed under general anesthesia, usually administered through an intravenous (IV) line. An incision is made through the abdomen to access the colon. Any cancerous or inflamed colon tissue is removed, and the remainder of the colon is sutured to the anus. On occasion, the colon tissue may be too inflamed to immediately attach to the anus, and a colostomy bag will be added until the colon is healthy enough to function properly. After the surgery, the abdominal incision is closed and the patient will spend two to three hours in the surgical recovery room.
Healing from a lower anterior resection takes about three to six weeks. During this time, a bowel management program will teach the patient how to regulate his bowel movements. The program includes instructions about the importance of body positioning when trying to have a bowel movement and how to manually stimulate a bowel movement.
Complications from the lower anterior resection are not as common as the more invasive abdominoperineal resection. There is a risk of excessive bleeding during and following the operation. An infection may set in from the opening of the bowels, resulting in a longer healing time. Swelling of the colon may also cause a longer recovery period.
Most patients have a favorable prognosis after the lower anterior resection. It is the operation performed most often for colorectal cancers as well as to remove inflamed or diseased colon tissue. Many patients are able to learn how to manage bowel movements after the procedure and avoid any fecal incontinence issues.