A colonoscopy is both a diagnostic and therapeutic procedure used to examine and treat the rectum, colon, and a portion of the terminal ileum. The procedure is performed with a colonoscope, a flexible and steerable instrument used to evaluate the entire colon (large intestine).
A colonoscopy is routinely used to screen for colon and rectal cancer. The American Cancer Society recommends healthy adults with no risk factors start screening for colorectal cancer at age 45 (the previous recommendation was 50 years).
Adults in good health and with a life expectancy of more than 10 years should continue regular colorectal cancer screening every 10 years through the age of 75.
After that, screening between ages 76 through 85 is based on a person’s preferences, life expectancy, overall health, and prior screening history.
Colon cancer often doesn’t have signs until the disease is advanced, so screening is important to detect potential cancer early.
Signs you may need to have a colonoscopy include:
- Changes in bowel habits
- Diarrhea
- Constipation
- Changes to the look of your stool
- Narrowing of the stool
- Feeling the need to have a bowel movement that's not relieved by having one
- Rectal bleeding with bright red blood
- Blood in the stool
- Stool may appear dark brown or black
- Weakness and fatigue, especially if accompanied unexplained weight loss
- Consistent abdominal pain, bloating, and cramping
Other symptoms of colon cancer may include:
- Low red blood cell counts (anemia) if the colon cancer bleeds into the digestive tract
- Yellowing skin and eyes (jaundice) if the cancer has spread to the liver
- Trouble breathing if the cancer has spread to the lungs
What Are Colonoscopies Used For?
Colonoscopies are also used to diagnose gastrointestinal (GI) disorders such as:
- Colon cancer
- Colon polyps
- Diverticulosis
- Inflammatory bowel disease (IBD)
Colonoscopy is also used to help determine the cause of:
- Gastrointestinal bleeding
- Rectal bleeding
- Changes in bowel habits, including diarrhea
- Abdominal pain
- Obstruction
- Abnormal X-rays or computerized tomography (CT) scans
- Unexplained weight loss
A colonoscopy can also be used to provide therapy and treatment such as:
- Removal of polyps
- Control of bleeding
What Is the Treatment for Colon Cancer?
Treatment for colon cancer may involve one or more of the following:
- Surgery
- Polypectomy and local excision for early-stage colon cancers
- Colectomy: surgery to remove all or part of the colon
- Colostomy or ileostomy
- Ablation and embolization, used for metastases (spread) of colon cancer to the lungs or liver
- Radiofrequency ablation (RFA)
- Microwave ablation (MWA)
- Ethanol (alcohol) ablation
- Cryosurgery (cryotherapy or cryoablation)
- Arterial embolization (also called trans-arterial embolization or TAE)
- Chemoembolization (also called trans-arterial chemoembolization or TACE)
- Radioembolization
- Chemotherapy
- 5-Fluorouracil (5-FU)
- Capecitabine (Xeloda), a pill that is changed into 5-FU once it gets to the tumor
- Irinotecan (Camptosar)
- Oxaliplatin (Eloxatin)
- Trifluridine and tipiracil (Lonsurf), a combination drug in pill form
- Radiation therapy (more often used to treat rectal cancer but may be used in combination with chemotherapy for colon cancer)
- Targeted therapy
- Drugs that target blood vessel formation (VEGF)
- Bevacizumab (Avastin)
- Ramucirumab (Cyramza)
- Ziv-aflibercept (Zaltrap)
- Drugs that target cancer cells with epidermal growth factor receptor (EGFR) changes
- Drugs that target cells with BRAF gene changes
- BRAF inhibitors: encorafenib (Braftovi)
- Kinase inhibitor
- Regorafenib (Stivarga)
- Drugs that target blood vessel formation (VEGF)
- Immunotherapy using immune checkpoint inhibitors
- PD-1 inhibitors
- Pembrolizumab (Keytruda)
- Nivolumab (Opdivo)
- CTLA-4 inhibitor
- Ipilimumab (Yervoy)
- PD-1 inhibitors
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https://www.uptodate.com/contents/overview-of-colonoscopy-in-adults?search=How%20Painful%20Is%20a%20Colonoscopy%3F&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1
https://gi.org/topics/colonoscopy/
https://www.niddk.nih.gov/health-information/diagnostic-tests/colonoscopy
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https://choosingwiselycanada.org/colonoscopy/
https://dighealth.org/blog/signs-you-may-need-to-schedule-a-colonoscopy/
https://www.cancer.org/cancer/colon-rectal-cancer.html