Colon resection is a surgical procedure that removes a diseased portion of the large intestine, or colon, to treat conditions like colorectal cancer, diverticulitis, and bowel obstructions. While the surgery is often successful in addressing the underlying medical issue, the body undergoes a period of adaptation afterward as the digestive system adjusts to its new structure. This recovery process can lead to a variety of lasting side effects.
Changes in Bowel Function
Following a colon resection, one of the most immediate and lasting adjustments involves changes in bowel habits. With less colonic surface area available, the large intestine’s capacity to absorb water from stool is diminished. This frequently leads to looser and more frequent bowel movements, a condition often described as chronic diarrhea. The digestive system, now shorter, moves waste through more quickly, contributing to this effect.
The initial postoperative period is marked by unpredictable bowel function, which can range from diarrhea to constipation. Constipation can occur as a side effect of pain medication or as the bowel temporarily slows down after surgery, a condition known as ileus. Over time, bowel patterns may stabilize, but many individuals find they need to manage ongoing changes in stool consistency and frequency.
A condition known as Low Anterior Resection Syndrome (LARS) can develop, particularly after surgery involving the removal of a portion of the rectum. LARS is characterized by a cluster of symptoms, including bowel frequency, urgency, and episodes of incontinence of gas or stool. Patients may experience clustering, where several bowel movements occur in a short period, followed by a period of relief. These symptoms are rooted in both the mechanical changes to the rectum and potential nerve alterations during the surgical procedure.
Beyond stool consistency, long-term changes in gas and bloating are also common. The alteration in anatomy can affect how the body processes and expels gas, leading to increased flatulence and abdominal bloating. Management often involves dietary adjustments and, in some cases, medication to help control symptoms.
Dietary Adjustments and Nutritional Deficiencies
The way the body processes food can be permanently altered after a colon resection, necessitating careful dietary management. Certain foods that were previously well-tolerated may now trigger uncomfortable symptoms like diarrhea, gas, and cramping. Common culprits include high-fiber foods, such as raw vegetables and whole grains, as well as fatty, greasy, or spicy meals. High-sugar foods can also exacerbate diarrhea for some individuals.
To manage these new sensitivities, many people find it helpful to keep a detailed food diary to identify specific trigger foods and patterns in their symptoms. Initially, a “low-residue” or low-fiber diet is often recommended to give the bowel time to heal and adapt. This involves favoring easily digestible foods like white bread, rice, and cooked vegetables over their high-fiber counterparts.
The removal of a segment of the colon can also create long-term risks for nutritional deficiencies. The colon plays a part in absorbing water and some nutrients, and its partial removal can interfere with this process. Iron-deficiency anemia can develop due to chronic low-level blood loss from the surgical site or impaired iron absorption.
Specific vitamins may also be affected, depending on which part of the intestine was removed. If the terminal ileum—the final section of the small intestine that connects to the colon—is removed along with the colon, the absorption of vitamin B12 can be significantly impaired. Deficiencies in fat-soluble vitamins, such as Vitamin D, may also occur. Because of these risks, regular blood tests to monitor nutrient levels are often recommended, with supplementation prescribed as needed.
Abdominal and Structural Complications
Surgery on the abdomen can lead to long-term structural issues that may not become apparent for months or even years. One of the more common complications is the development of an incisional hernia. This occurs when internal tissue, such as the intestine, pushes through the weakened muscle wall at the site of the surgical scar. A visible bulge near the incision, which may become more prominent when coughing or straining, is a primary sign.
Another long-term issue is the formation of adhesions, which are bands of internal scar tissue. While adhesions are a natural part of the body’s healing process, they can sometimes cause problems by making organs and tissues stick together. This can lead to chronic, intermittent abdominal pain or cramping as the adhesions pull on internal structures.
In some instances, these bands of scar tissue can cause a partial or complete bowel obstruction by kinking or twisting the intestine. A bowel obstruction prevents the normal passage of stool and gas and requires prompt medical attention. Symptoms include:
- Severe pain
- Bloating
- Nausea
- Vomiting
Nerve-Related and Pelvic Floor Issues
Surgery deep within the pelvis, particularly for rectal cancer, can impact the autonomic nerves that control urinary, sexual, and bowel functions. This nerve damage, which can result from direct injury, stretching, or inflammation during the procedure, may lead to long-term complications. The effects of this nerve impact are distinct from the mechanical changes to the bowel itself.
For patients who undergo an abdominoperineal resection, where the rectum and anus are removed, a phenomenon known as phantom rectal pain can occur. This condition involves feeling pain or the sensation of needing to have a bowel movement, even though the rectum is no longer present. It is a nerve-related issue, similar to phantom limb pain, where the brain continues to receive signals from nerves that were once connected to the removed organ.
The proximity of the surgical area to nerves controlling the bladder and reproductive organs means these functions can also be affected. Some individuals may experience long-term bladder issues, such as urinary urgency, frequency, or incontinence. Similarly, sexual function can be altered, with potential side effects including erectile dysfunction or changes in ejaculation in men, and painful intercourse (dyspareunia) in women.