Reversing a colostomy requires surgery where the surgeon takes the end of the colon that feeds into the colostomy bag and reattaches it to the remaining section of colon within the body, according to NHS Choices. Both loop and end colostomies can be reversed.
Some colostomies are only intended to be temporary, but a number of conditions must be met before they can be reversed, says NHS Choices. Before the colostomy can be reversed, a patient must recover fully from the initial colostomy procedure, a process that commonly takes about 12 weeks. The waiting period can be extended, however, if the patient is undergoing other treatments such as chemotherapy or has other health issues that render surgery more risky. Depending on the circumstances, even a colostomy that can be reversed might be left in place for years.
There are several reasons why temporary colostomies are performed, according to MedlinePlus. An infection of the abdomen from perforated diverticulitis or an abscess is one reason. An infection of the perineum can also necessitate the procedure. An injury to the colon or rectum, such as from a gunshot wound, also often requires a colostomy. A bowel obstruction or colon cancer sometimes requires a colostomy.