Screening Colonoscopy
Colonoscopy is the use of an endoscope to fully visualize the colon and the rectum. There are two types of colonoscopy; screening or therapeutic colonoscopy. In most regions, screening colonoscopy has been adopted for persons at a predetermined age regardless of their symptomatic status. The screening colonoscopy is mainly indicated for anyone > 50 years of age, of African American descent with a positive family history of colorectal polyps or carcinomas.
This screening is important because it helps reduce the mortality rates of colorectal carcinomas with early detection. It also prevents the increased incidence of disease as it can be used for the resection of the mucosal polyps. Colonoscopy is an appropriate procedure compared to other radiological modalities because it serves three main purposes: biopsies can be taken from areas of abnormality for pathological assessment, the resection of small polyps which are present during the colonoscopy screening is possible and the diagnosis of large polyps.
Indications
Screening colonoscopy is also used to assess abnormal gastrointestinal symptoms such as rectal bleeding, chronic diarrhea or constipation which are strong indicators of an underlying abnormality. Therapeutic colonoscopy is described by the resection of mucosal polyps otherwise referred to as polypectomies.
After the screening colonoscopy, if there is a negative finding, the next screening is to be done in 10 years. If there are positive findings and a strong family history of polyps or colorectal cancers (this may include small cysts, adenomatous polyps) the next screening is to be done in 5 years or less to prevent the development of cancerous lesions until it is too late for treatment.
How is the procedure done
The procedure takes at least 60 minutes when done with a specially trained professional.
Before the procedure, the patient is put on laxatives and diet control for a period of two weeks. The patient is meant to fast the night before the procedure to clean out the bowel as much as possible to allow easy visibility of the mucosa. Right before the procedure, patient consent is taken and the whole procedure is explained to them.
The patient puts on a hospital gown and lays on their left side on the table with knees brought to the chest. They are put under general anesthesia and the anal area is sterilely readied for the procedure. Air is filled into the colon to allow maximum visualization of the mucosa. Using a colonoscope, it is inserted via the anal orifice, up into the rectum, sigmoid colon, descending colon, transverse colon, ascending colon to the ileum. Biopsies of abnormal areas are taken for further investigation. Random biopsies can also be taken to rule out microscopic colitis. The colonoscope is slowly withdrawn as the mucosa is still being examined. The patient is discharged on the same day unless there’s a complication. The biopsies taken are submitted to the lab for investigations.
Risks
There are various risks encountered during colonoscopy. Intestinal perforation is rare abut can happen when the colonoscope is being manipulated through the lumen. It can also arise after a polypectomy. These perforations are managed by bed rest and watchful waiting and antibiotics but if they are large tears, a surgical repair is necessary.
Postsurgical bleeding which manifests as blood in stool especially after polypectomy.
Recovery
Most of the complications arise during recovery; therefore, a review appointment date is set 2 weeks post the surgical procedure for evaluation and monitoring.
The patient is still put on dietary control, watching the portion size and he is to avoid intake of alcohol the first 24 hours post-procedure.
Thepatient might feel bloated due to the gas put in the colon but it soon resolves. Slight bleeding normally occurs if a biopsy was taken, they should report back to the doctor if the bleeding is excessive immediately. Slight bowel and rectal irritation or pain is likely after the anesthesia wears off but this is managed by adequate administration of analgesics. If the pain persists and the patient develops a fever, the patient should immediately go back to the doctor as this signifies the onset of an infection.
Outcomes
The colonoscopy results should be reported as positive or negative based on whether visualization of abnormal findings such as a polyp or growths in the mucosa and vice versa for a negative result.
There is a generally good outcome after the procedure; very few perforations have been recorded to have occurred.
Biopsy results are received in a span of about 3 weeks that determines whether the lesions are cancerous, noncancerous or precancerous.