The side effects of colorectal surgery depend on several factors, including the kind of operation performed and the patient’s overall health. Most people will have pain after surgery—especially patients who underwent an open surgery that utilized one large incision—and this pain may require medication for a few days thereafter. Initially, the patient may also need to ingest nutrients through IV fluids, although problems related to eating and digestion should resolve themselves within a couple days.
Other potential side effects include bleeding from surgery, blood clots in the legs and damage to nearby organs during the operation. In rare cases, the newly forged connections between the ends of the intestines may leak, which can lead to infection. Also, the abdominal incision may open and become an open wound. Some patients also develop scar tissue that can cause organs or tissues to stick together; these adhesions can sometimes block the bowel and necessitate another surgery.
In addition, some patients may need or temporary or permanent colostomy or ileostomy after surgery. These are surgical openings in the skin that allow waste to leave from the intestines. Men undergoing a procedure called an abdominoperineal resection may have sexual and fertility-related difficulties, including an inability to stop an erection or reach orgasm. This surgery may damage the nerves that control ejaculation, leading to orgasms without semen or retrograde ejaculation, in which the semen goes backward into the bladder during orgasm.