Colon Cancer Surgery Specialist In Bozeman, Montana

What is colon cancer?

Colon cancer develops when abnormal cells grow uncontrollably within the colon, or large intestine.

Most colon cancers begin in polyps, which are growths arising from the inner surface of the colon. Polyps then gradually acquire cellular changes that allow them to become cancerous. Finding and removing precancerous polyps during colonoscopy can prevent many colon cancers from developing.

Once cancer forms, however, it can grow through the wall of the colon, spread to nearby lymph nodes, or travel to organs such as the liver or lungs.

What increases the risk of colon cancer?

Colon cancer can occur without an obvious cause, but recognized risk factors include:

• Increasing age
• A personal history of colon polyps or colorectal cancer
• A family history of colon or rectal cancer
• Inherited cancer syndromes
• Crohn’s disease or ulcerative colitis involving the colon
• Smoking
• Heavy alcohol use
• Obesity and physical inactivity
• A diet high in processed meat and low in fiber

Some patients should begin screening earlier or undergo genetic evaluation because of their personal or family history.

What symptoms can colon cancer cause?

Early colon cancer often causes no symptoms, which is why routine screening is so important.

When symptoms occur, they may include:

• Rectal bleeding or blood in the stool
• Iron-deficiency anemia
• A persistent change in bowel habits
• Narrowing of the stool
• Abdominal pain or bloating
• Unexplained weight loss
• Fatigue
• Nausea or vomiting
• Symptoms of intestinal obstruction

These symptoms can also result from noncancerous conditions, but they deserve timely evaluation.

How is colon cancer diagnosed and staged?

Most colon cancers are diagnosed during colonoscopy, which allows the gastroenterologist to examine the colon and obtain a biopsy.

After cancer is confirmed, staging usually includes blood tests, measurement of carcinoembryonic antigen, or CEA, and imaging of the chest, abdomen, and pelvis. Tumor testing may identify inherited risk, predict response to certain medications, and help guide treatment.

The treatment plan depends on how deeply the cancer has grown, whether lymph nodes are involved, whether the cancer has spread, the tumor’s molecular characteristics, and the patient’s overall health.

How is colon cancer treated?

Surgery is the primary treatment for localized colon cancer. The operation removes the tumor, the affected segment of colon, its blood supply, and the regional lymph nodes. The healthy ends of the bowel are then reconnected.

Some patients also require chemotherapy. Whether chemotherapy is recommended depends on the cancer stage, lymph-node involvement, high-risk features, tumor biology, and final pathology.

Patients with metastatic disease may benefit from chemotherapy, immunotherapy, targeted treatment, liver or lung surgery, ablation, or a combination of treatments. These decisions are made through multidisciplinary cancer planning.

What does colon cancer surgery involve?

The specific operation depends on the tumor’s location. Procedures may include:

• Right colectomy
• Extended right colectomy
• Transverse colectomy
• Left colectomy
• Sigmoid colectomy
• Subtotal or total colectomy

Dr. Zehnpfennig performs colon cancer surgery using advanced robotic and laparoscopic techniques while adhering to oncologic principles. Through several small incisions, he removes the cancer-bearing segment and associated lymph nodes while preserving healthy bowel whenever oncologically appropriate.

The bowel division and anastomosis are completed entirely within the abdomen. In this totally intracorporeal approach, the colon is never brought outside the body during the operation. This avoids the traction, twisting, and manipulation required to deliver the bowel through an abdominal incision for reconstruction. In right colectomy, totally intracorporeal anastomosis is associated with earlier return of bowel function, less postoperative pain, smaller extraction incisions, and a lower risk of prolonged postoperative ileus in several comparative studies.³˒⁴

Can natural-orifice specimen extraction be used for colon cancer?

For selected patients, the intact cancer specimen can be removed through a natural opening rather than through a larger abdominal extraction incision.

Eligibility depends on the size and location of the tumor, the dimensions of the specimen, patient anatomy, and whether the specimen can be removed intact without compromising cancer surgery principles and oncologically-sound technique.

Compared with conventional abdominal specimen extraction, natural-orifice colorectal surgery is associated with less postoperative pain, fewer wound-related complications, faster return of bowel function, and shorter hospitalization.¹˒²

If natural-orifice extraction is not appropriate, Dr. Zehnpfennig completes the resection and bowel connection inside the abdomen and places a limited extraction incision in the safest and least traumatic location on the abdomen.

Will I need a colostomy?

Most patients undergoing planned colon cancer surgery do not require a colostomy.

A temporary or permanent ostomy may be necessary when cancer causes obstruction or perforation, infection is severe, the patient is unstable, multiple organs are involved, or safely reconnecting the bowel is not possible.

What is recovery like after colon cancer surgery?

Dr. Zehnpfennig follows an enhanced recovery pathway that combines minimally invasive surgery, multimodal pain control, early reintroduction of diet, and early mobilization.

Many patients meet discharge criteria on the first postoperative day, and selected patients may qualify for same-day discharge. Most patients can return to normal, unrestricted activity after two weeks.

The pathology report is reviewed after surgery to determine the final stage and whether additional treatment is appropriate.

Why does surgical experience matter?

Successful colon cancer surgery requires more than removing the visible tumor. The operation must follow the correct embryologic tissue planes, remove the associated blood vessels and lymphatic drainage, preserve surrounding structures, and create a secure bowel connection.

Dr. Zehnpfennig has performed more than 1,000 robotic operations and specializes in completely intracorporeal colorectal surgery, natural-orifice specimen extraction, and enhanced recovery. He tracks his operative outcomes and discusses his experience and expected results directly with patients.

To arrange a colon cancer surgery consultation, call the office or request an appointment online.

1. Cao L, et al. Evaluation of the efficacy of natural-orifice specimen extraction surgery versus conventional laparoscopic surgery for colorectal cancers: a systematic review and meta-analysis. Colorectal Disease. 2025.

2. Huang L, Wang JQ. Comparative analysis of natural-orifice and conventional transabdominal specimen extraction in robot-assisted colorectal cancer resection: a systematic review and meta-analysis. Journal of Robotic Surgery. 2024;18:360.

4. Allaix ME, et al. Randomized clinical trial of intracorporeal versus extracorporeal anastomosis in laparoscopic right colectomy. British Journal of Surgery. 2019.

5. Cheong C, et al. Intracorporeal versus extracorporeal anastomosis in minimally invasive right hemicolectomy: systematic review and meta-analysis of randomized controlled trials. Annals of Surgical Treatment and Research. 2024.