Anyone who has undergone a colonoscopy knows that it is a long and rather uncomfortable procedure.
To prepare, many doctors advise the patients to undergo certain diet or fluid restrictions, often involving oral laxatives or limiting solid foods a few days prior to the test. The actual examination lasts for about 30–60 minutes, and the patient is usually on medications to help them relax during this time. The patient lies on his left side while the doctor anally inserts a long, flexible tube that goes through the colon and sends images of the lining to the doctor to check for abnormalities.
The patient may feel cramping during this procedure, but all of this discomfort is necessary to ascertain whether abnormal growths or other issues are occurring internally and are causing abdominal pain, rectal bleeding, or other symptoms. 
Instead of inserting a tube with a camera, the doctor gives the patient a pill with a camera device inside it. The patient swallows it, and the pill takes thousands of pictures as it works its way through the gut, and transmits them to a data recorder the patient wears around the waist.
Best of all, it’s able to check parts of the bowel that a traditional colonoscopy is unable to reach, like the small intestine.
Here’s how it works (though the process may differ depending on the hospital and individual case):
Laxatives may be prescribed to empty the patient’s bowels and the patient is usually told not to eat after lunch the day before the procedure and only drink water the day of the test. At the hospital for the morning appointment, the patient either puts on a belt with sensors or the technician applies sticky pad sensors to the chest and stomach. Then the technician attaches a data tracker to a belt around the patient’s waist. Next, the patient swallows the capsules with the camera in it with some water. The patient returns home with the instructions to avoid drink for two hours and to eat a light snack after four hours but nothing else until after the examination (usually about eight hours after taking the pill.)
The patient returns to the hospital later that afternoon and the technician checks if the pill has reached the large bowel. If it has, the camera should be taking pictures as it goes along and sending it to the data tracker. The belt and sensors are removed and the procedure is over. If the pill has not yet reached the large bowel, the patient returns home and keeps the sensors and data recorder on until the recorder’s batteries die (usually after 12–14 hours) and the patient returns it to the hospital the following morning. The doctor examines the pictures downloaded from the data tracker, and there’s no need to worry about the camera pill. It is disposable and will leave the body the next time the patient needs the bathroom.  Why is Capsule Colonoscopy Needed? There are a multitude of reasons why a doctor would prescribe this procedure. One of the most common is to check for cancer, with colorectal cancer being the second-leading cause of cancer deaths in men and the third in women. Early detection is vital to reduce mortality rates.
“The video capsule system is the only alternative screening method for colon cancer that allows for direct visualization of colon polyps,” said Mukund Venu, MD, the director of clinical operations and director of diagnostic testing for Loyola Medicine’s division of gastroenterology. “Early detection has been proven to save lives, and the video capsule system offers a convenient screening test for people who are unable to have a complete colonoscopy.” 
Other reasons for the procedure include: Finding the cause of gastrointestinal bleeding Diagnosing Crohn’s disease and other inflammatory bowel diseases Diagnosing celiac disease Examining the esophagus Following up on other tests like X-rays Capsule Endoscopy vs Colonoscopy Colonoscopies are still considered the gold standard for diagnosing lower gastrointestinal diseases , however, they do have their limitations. The major one being their inability to visually inspect anything beyond the colon like the small intestine. Typically capsule endoscopies are reserved for instances where traditional endoscopies or colonoscopies have failed . Colonoscopies also allow for the concurrent treatment of intestinal polyps (via polypectomy) whereas capsule endoscopies only provide passive visual information.
Risks of a Capsule Colonoscopy Overall, this is considered a very safe procedure, but there are a few risks. A fear that many people have when they hear about this process is that the camera pill will get “stuck” in the digestive tract instead of leaving in a bowel movement. It’s a small risk, but it’s more likely to occur with people with tumors, strictures, Crohn’s, surgeries in those areas, or other conditions that cause a narrowing in the digestive tract. If this is a cause for concern, your doctor will have CT scan before prescribing the procedure to check for this narrowing. If the patient doesn’t see the capsule in their bowels for two weeks after the colonoscopy, it’s recommended to contact the doctor for an X-ray to see if it’s still there. 
However, the risk of this is small, and a capsule colonoscopy is more comfortable and less intrusive than the traditional kind, which many patients are thankful for. So, can capsule endoscopy replace a colonoscopy? In certain circumstances, yes, however, this decision will ultimately be made by your doctor. Overall, colonoscopies are still considered the gold standard in most situations, though capsule endoscopy is certainly a welcome addition to doctors and patients alike. Disclaimer: This information is not intended to be a substitute for professional medical advice, diagnosis or treatment and is for information only. Always seek the advice of your physician or another qualified health provider with any questions about your medical condition and/or current medication. Do not disregard professional medical advice or delay seeking advice or treatment because of something you have read here.