1. Take the Tummy Trouble Quiz
2. Digestive Disease Myths Slideshow Pictures
3. Heartburn? Foods to Eat, Foods to Avoid Slideshow

Medical Author:

R Benjamin Saldana, DO

Medical Editor:

John P. Cunha, DO, FACOEP

John P. Cunha, DO, FACOEP

John P. Cunha, DO, is a U.S. board-certified Emergency Medicine Physician. Dr. Cunha's educational background includes a BS in Biology from Rutgers, the State University of New Jersey, and a DO from the Kansas City University of Medicine and Biosciences in Kansas City, MO. He completed residency training in Emergency Medicine at Newark Beth Israel Medical Center in Newark, New Jersey.

View Full Profile

Other tests can help a doctor detect diseases of the colon. Sometimes these tests can be done instead of a colonoscopy, but at other times they are performed in addition to a colonoscopy because each test can provide different types of information.

• With similar preparation, a special X-ray examination of the entire colon, a barium enema, can be used instead of or in addition to colonoscopy. For this test, a liquid called barium is inserted into the colon using a small tube through the anus. X-rays are then taken of the abdomen with the barium inside. This liquid is seen on the X-ray and is used to outline the irregularities of the bowel wall.
• Another test called a sigmoidoscopy can be performed. This test is very similar to a colonoscopy but requires less preparation. The instrument used, a sigmoidoscope, is 2 ft long and allows visualization of the anal canal, rectum, and the part of the colon closest to the rectum known as the sigmoid colon. Although this test is important, it does not allow detection of abnormalities in other areas of the colon because the sigmoidoscope is much shorter than the colonoscope.
• CT scans are often used to investigate abnormalities of the abdomen. Gastrografin is a liquid similar to barium, which allows the bowel to be better seen during a CT scan. This liquid, also called oral contrast, is swallowed and then allowed to pass from the stomach, through the small intestine (the ileum) and then through the large intestine (the colon) before the CT scan is performed. In this way, a CT scan can be helpful to investigate abdominal and bowel problems.
• Other tests include balloon endoscopy, push endoscopy, and virtual colonoscopy.

Your doctor will decide which of these tests is most appropriate for you.

Picture of the anatomy of the colon

Picture of colon cancer and colon polyps

Picture of diverticulitis

Picture of Crohn's disease

Picture of ulcerative colitis

Must Read Articles Related to Colonoscopy

Anatomy of the Digestive System Digestion is the process in which food is broken into smaller pieces so the body can use them to build and nourish cells and provide energy. The digestive syste...learn more >>

Clostridium Difficile (C. difficile, C. diff) Clostridium difficile (or C. difficile, C. diff) colitis is an infection of the colon. C. diff infection is most commonly associated with antibiotic use. Anothe...learn more >>

Colitis Colitis is an inflammation of the colon. There are many cause of colitis, infectious colitis (bacterial or viral), ischemic colitis, inflammatory bowel disease ...learn more >>

See the Entire Colonoscopy Topic Guide »