Does surgery of primary cancer of the rectosigmoid junction require a colostomy?

Very unlikely: The rectosigmoid junction is well above the anal sphincter. Colostomy becomes more likely as the primary tumor gets closer to the anus.

Usually not: Everybody's case however is unique, and there could be circumstances where a colostomy is needed, but it is unusual for planned operation.

Very rarely: There are 3 reasons why a stoma may be needed: 1-if the cancer is so close to the anus that removal would leave too little to re-connect to. Using modern techniques, this is very rare. 2-if the cancer caused complete blockage or perforation requiring emergency surgery, a temporary stoma may be necessary. 3-if we are concerned that the new connection may leak, we temporarily divert w/an ileostomy.