Colorectal Cancer Diagnosis & Treatment

Colorectal Cancer Diagnostic Testing

If you have colorectal cancer, it’s natural to be concerned—but you can also be hopeful. Mercy offers the latest screening tools, diagnostic tests and treatments for all types of colorectal cancer, no matter the stage.

Screening for Colon Cancer

Colon cancer screening tests can often detect colon cancer at its earliest stages when treatment is most likely to be successful. The most common colon and rectal cancer screenings are colonoscopies, sigmoidoscopies and high-sensitivity fecal occult blood tests (FOBTs). If your screening test shows a potential concern or you’re experiencing symptoms, your Mercy gastroenterologist may recommend diagnostic testing, which can include certain types of imaging tests, biopsies and laboratory tests.

Diagnostic Imaging 

Imaging tests are used in determining the staging and spreading of colon cancer. The types of imaging used to diagnose colon cancer may include:


Biopsies are performed if colon or rectal cancer is suspected by screening or diagnostic tests. A biopsy is usually completed during a colonoscopy and often performed using the minimally invasive laparoscopic method.

Blood Tests

Certain laboratory tests may be ordered to help determine if you have colon cancer. These blood tests can also be used to help monitor your cancer once diagnosed. The types of blood tests may include:

  • Complete blood count (CBC)
  • Liver enzymes
  • Tumor markers

Colorectal Cancer Treatment

When you rely on the team of cancer specialists at Mercy, you’ll find complete, compassionate colorectal cancer care from detection and diagnosis to treatment and recovery. We develop personalized cancer treatment based on your individual needs, the stage of your colorectal cancer and whether it has spread or not. Treatments include colon cancer surgery, radiation therapy, chemotherapy, immunotherapy and targeted therapy.

Colorectal Cancer Surgery

Colon cancer surgery is a common treatment for all stages of colorectal cancer. During surgery for colon cancer, lymph nodes are usually removed to determine whether they’re cancerous. Depending on the location and type of colorectal cancer, one or more surgeries may be performed. Mercy surgeons specialize in removing polyps and tumors and are skilled in the latest technologies and minimally invasive colorectal surgery techniques, including laparoscopic surgery and robotic-assisted surgery for colon cancer.

  • Laparoscopic surgery uses a lighted tube (or scope) and small incisions to remove cancer or parts of the colon and rectum
  • Robotic-assisted surgery offers enhanced precision and shorter recovery times for colon cancer surgeries.

Polypectomy & Local Excision

Some early-stage colon cancers can be removed during a colonoscopy. Both polypectomy and local excision can be performed during this procedure.

  • Polypectomy is generally performed for early-stage colon cancer removal and is performed during the removal of polyps. This surgery uses a loop instrument is used to remove cancerous polyps from the colon wall.
  • Local excision can treat cancers in the rectum (lowest part of your colon) by removing small cancers and some nearby healthy tissue from the colon or rectum.

Bowel Resection

Bowel resection, also called a colectomy, removes the diseased portion of the colon or rectum. The nearby lymph nodes are also removed during a bowel. resection in order to be tested for cancer. If possible, the two healthy parts of the colon or rectum are sewn together (also called an anastomosis).


In many cases, patients will not need a colostomy after colorectal cancer surgery. However, there are instances in which the bowel cannot be immediately reattached and a temporary colostomy may be needed. A colostomy creates an opening on the outside of the body that collects waste in a pouch. 

Radiation Therapy for Colorectal Cancer

Mercy radiation oncologists offer advanced radiation therapy treatments to precisely target cancerous tumors and may be used before or after colorectal cancer surgery. It’s also used as palliative therapy for people who can’t have surgery and need relief from discomfort caused by tumors. Types of radiation therapy for colorectal cancer include external radiotherapy and brachytherapy or internal radiation therapy.

External Radiation Therapy

External beam radiation therapy (EBRT) is a local cancer treatment and is most often used for patients with colon or rectal cancer. The different types of external radiotherapy used for colorectal cancers may include:

  • Intensity-modulated radiation therapy (IMRT) – IMRT uses external radiation beams targeted to a tumor’s size and shape.
  • Stereotactic radiotherapy (SRS) – SRS delivers high doses of radiation to extremely precise locations to protect nearby tissues. CyberKnife is a type of SRS that is often used for colon cancer by targeting complex cancer tumors that can’t be surgically removed with multiple high doses of radiation.

Internal Radiation Therapy

Internal radiation therapy, also known as brachytherapy, might be used to treat some types of rectal cancers. During brachytherapy, radioactive material is placed inside or near cancer tumors to target smaller treatment areas.

Chemotherapy for Colon Cancer

For some colorectal cancers, chemotherapy may be needed before or after surgery. Chemo drugs target cancer cells that grow and divide quickly. Chemo can be administered by infusion into your veins or orally to fight cancer throughout your body.

Immunotherapy for Colon Cancer

Immunotherapy is used in certain colorectal cancers to help improve treatment options. Many people who have taken immunotherapy medications have reported experiencing fewer side effects than traditional chemotherapies.

Targeted Therapy for Colon Cancer

Targeted therapies are drugs that target gene and protein changes in cells involved with colorectal cancer. An example is monoclonal antibodies—substances made in a lab that can help your immune system find and attack cancer cells.


Common Questions About Colon Cancer

Dr. Chad Wigington

Learn about colon cancer risks, screening guidelines and treatment options from Dr. Wigington, a Mercy Clinic gastroenterologist.

Colorectal Cancer Care

At Mercy, we offer more than medical treatments. We’ll help you understand your condition and your options, so you can make well-informed decisions about your care.