A colonoscopy is an exam used to look for changes — such as swollen, irritated tissues, polyps or cancer — in the large intestine (colon) and rectum. During a colonoscopy, a long, flexible tube (colonoscope) is inserted into the rectum. A tiny video camera at the tip of the tube allows the doctor to view the inside of the entire colon. If necessary, polyps or other types of abnormal tissue can be removed through the scope during a colonoscopy. Tissue samples (biopsies) can be taken during a colonoscopy as well

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International Islamic University Chittagong (IIUC)
Department of Pharmacy
Course Code: Pharm- 2404
Course Title: Biochemistry and molecular biology- 1 lab
Subject: Colonoscopy
Submitted to: Md. Ashraf Uddin Chowdhury.
Lecturer, Department of pharmacy, (IIUC).
Submitted by:
ID No : P213034
Semester : 4th
Session : Spring-23
Section : Male
Gmail Address : p213034@ugrad.iiuc.ac.bd
Contact No : 01783975363
Date of submission : 12-05-2023

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COLONOSCOPY
1. INTRODUCTION:
Principle: A colonoscopy is an exam used to look for changes — such as swollen, irritated
tissues, polyps or cancer — in the large intestine (colon) and rectum.
During a colonoscopy, a long, flexible tube (colonoscope) is inserted into the rectum. A tiny
video camera at the tip of the tube allows the doctor to view the inside of the entire colon.
If necessary, polyps or other types of abnormal tissue can be removed through the scope
during a colonoscopy. Tissue samples (biopsies) can be taken during a colonoscopy as well.
Figure: Colonoscopy

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General info: Doctor may recommend a colonoscopy to:
Investigate intestinal signs and symptoms. A colonoscopy can help a doctor explore
possible causes of abdominal pain, rectal bleeding, chronic diarrhea and other intestinal
problems.
Screen for colon cancer. If a person’s age 45 or older and at average risk of colon cancer
— he may have no colon cancer risk factors other than age — then doctor may recommend
a colonoscopy every 10 years. If he has other risk factors, then a doctor may recommend a
screen sooner. Colonoscopy is one of a few options for colon cancer screening. Talk with a
doctor about the best options of it.
Look for more polyps. If a person has had polyps before, then a doctor may recommend a
follow-up colonoscopy to look for and remove any additional polyps. This is done to reduce
his risk of colon cancer.
Treat an issue. Sometimes, a colonoscopy may be done for treatment purposes, such as
placing a stent or removing an object in a person’s colon.
2. MATERIAL AND METHOD:
Chemical: Polyethylene glycol-electrolyte solution (PEG-ES) is used to empty the colon
(large intestine, bowel) before a colonoscopy (examination of the inside of the colon to
check for colon cancer and other abnormalities) or barium enema (a test in which the colon
is filled with a fluid and then x-rays are taken) so that the doctor will have a clear view of
the walls of the colon. PEG-ES is in a class of medications called osmotic laxatives. It works
by causing watery diarrhea so that the stool can be emptied from the colon. The medication
also contains electrolytes to prevent dehydration and other serious side effects that may be
caused by fluid loss as the colon is emptied.
Figure: Polyethylene glycol-electrolyte solution (PEG-ES)

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Equipment: During a colonoscopy, the doctor uses a colonoscope, a long, flexible, tubular
instrument about 1/2-inch in diameter that transmits an image of the lining of the colon so
the doctor can examine it for any abnormalities. The tube has a light and a tiny camera on
one end. The colonoscope is inserted through the rectum and advanced to the other end of
the large intestine.
Figure: Colonoscope.
Figure: Colonoscopy machine.

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Procedure: A doctor performs a colonoscopy in a hospital or an outpatient center. A
colonoscopy usually takes 30 to 60 minutes.
A health care professional will place an intravenous (IV) needle in a vein in a person’s arm
or hand to give him sedatives, anaesthesia, or pain medicine, so he won’t be aware or feel
pain during the procedure. The health care staff will check his vital signs and keep him as
comfortable as possible.
For the procedure, he’ll lie on a table while the doctor inserts a colonoscope through his
anus and into his rectum and colon. The scope inflates his large intestine with air for a better
view. The camera sends a video image to a monitor, allowing the doctor to examine his
large intestine.
The doctor may move him several times on the table to adjust the scope for better viewing.
Once the scope reaches the opening to his small intestine, the doctor slowly removes the
scope and examines the lining of his large intestine again.
During the procedure, the doctor may remove polyps and will send them to a lab for testing.
He will not feel the polyp removal. Colon polyps are common in adults and are harmless in
most cases. However, most colon cancer begins as a polyp, so removing polyps early helps
to prevent cancer.
If a doctor finds abnormal tissue, he or she may perform a biopsy. He or she won’t feel the
biopsy.

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Precaution: Follow a special diet the day before the exam.
Typically, a person won't be able to eat solid food the day before the exam. Drinks may be
limited to clear liquids — plain water, tea and coffee without milk or cream, broth, and
carbonated beverages. Avoid red liquids, which can be mistaken for blood during the
colonoscopy.
After the exam, it takes about an hour to begin to recover from the sedative. He'll need
someone to take him home because it can take up to a day for the full effects of the sedative
to wear off. Don't drive or make important decisions or go back to work for the rest of the
day.
He or she may feel bloated or pass gas for a few hours after the exam, as he or she clear the
air from his or her colon. Walking may help relieve any discomfort.
He or she may also notice a small amount of blood with the first bowel movement after the
exam. Usually this isn't cause for alarm. Consult a doctor if he or she continue to pass blood
or blood clots or if he or she have persistent abdominal pain or a fever. While unlikely, this
may occur immediately or in the first few days after the procedure, but may be delayed for
up to 1 to 2 weeks.
3. Result:
A doctor will review the results of the colonoscopy and then share the results with his
patients.
Negative result
A colonoscopy is considered negative if the doctor doesn't find any abnormalities in the
colon.
Then a doctor may recommend that he or she may have another colonoscopy:
 In 10 years, if he or she at average risk of colon cancer and he or she may have no colon
cancer risk factors other than age or if he or she have benign small polyps.

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 In 1 to 7 years, depending on a variety of factors: The number, size and type of polyps
removed; if he or she have a history of polyps in previous colonoscopy procedures; if he
or she have certain genetic syndromes; or if he or she have a family history of colon
cancer.
If there was residual stool in the colon that prevented complete examination of his or her
colon, then doctor may recommend a repeat colonoscopy. How soon will depend on the
amount of stool and how much of his or her colon was able to be seen. His or her doctor
may recommend a different bowel preparation to ensure that his or her bowel is completely
emptied before the next colonoscopy.
Positive result
A colonoscopy is considered positive if the doctor finds any polyps or abnormal tissue in
the colon.
Most polyps aren't cancerous, but some can be precancerous. Polyps removed during
colonoscopy are sent to a laboratory for analysis to determine whether they are cancerous,
precancerous or noncancerous.
Depending on the size and number of polyps, he or she may need to follow a more rigorous
surveillance schedule in the future to look for more polyps.
If his or her doctor finds one or two polyps less than 0.4 inch (1 centimeter) in diameter, he
or she may recommend a repeat colonoscopy in 7 to 10 years, depending on his or her other
risk factors for colon cancer.
Doctor will recommend another colonoscopy sooner if his or her have:
 More than two polyps
 A large polyp — larger than 0.4 inch (1 centimeter)
 Polyps and also residual stool in the colon that prevents complete examination of the
colon
 Polyps with certain cell characteristics that indicate a higher risk of future cancer
 Cancerous polyps
If his or her have a polyp or other abnormal tissue that couldn't be removed during the
colonoscopy, then doctor may recommend a repeat exam with a gastroenterologist who has
special expertise in removing large polyps, or surgery.

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Problems with his or her exam
If his or her doctor is concerned about the quality of the view through the scope, he or she
may recommend a repeat colonoscopy or a shorter time until his or her next colonoscopy.
If his or her doctor was unable to advance the scope through his or her entire colon, a virtual
colonoscopy may be recommended to examine the rest of his or her colon.
4. Discussion: A colonoscopy is an exam of the lower part of the gastrointestinal tract, which
is called the colon or large intestine (bowel). Colonoscopy is a safe procedure that provides
information other tests may not be able to give. Colonoscopy is performed by inserting a
device called a colonoscope into the anus and advancing through the entire colon. The
procedure generally takes between 20 minutes and one hour. Colonoscopies can detect
conditions like colitis, inflammatory bowel disease and diverticulosis. But mainly, doctors
are looking for precancerous or cancerous colon polyps, which are growths on the inside of
the colon's lining.
5. Reference:
1. Colonoscopy. National Institute of Diabetes and Digestive and Kidney Diseases.
https://www.niddk.nih.gov/health-information/diagnostic-tests/colonoscopy. Accessed April 1,
2022.
2. Lee L, et al. Overview of colonoscopy in adults. https://www.uptodate.com/contents/search.
Accessed April 1, 2022.
3. Ask Mayo Expert. Colorectal cancer: Screening and management (adult). Mayo Clinic; 2021.
4. Screening for colorectal cancer: U.S. Preventive Services Task Force Recommendation
Statement. Journal of the American Medical Association. 2021; doi:10.1001/jama.2021.6238.
5. A-Rahim YI. Bowel preparation before colonoscopy in adults.
https://www.uptodate.com/contents/search. Accessed April 1, 2022.