Colonoscopy
Colonoscopy allows the doctor to look into the interior lining of the large intestine. Through this procedure, the doctor is able to detect inflamed tissue, abnormal growths, polyps, tumors and ulcers. Early signs of cancer in the colon and the rectum can also be detected through colonoscopy. This procedure is also used to study unexplained changes in bowel habits, to evaluate symptoms of abdominal pain, rectal bleeding and sudden weight loss. The colonoscope is a thin flexible instrument whose length ranges from 48 inches to 72 inches. A small video camera is attached to the colonoscope so that photographic, electronic or videotaped images of the large intestine can be taken. Colonoscope is used to view the entire colon as well as a small portion of the lower small intestine.
The colon should be completely empty for colonoscopy to be thorough and safe. The liquid diet should be clear of any food colorings. It should be fat free. The colonoscope is gradually inserted into the rectum and slowly guided into the colon. The scope transmits an image of the inside of the colon onto a video screen so that the doctor can carefully examine the lining of the colon. The scope blows air into the colon and inflates it so that the doctor has a better view of the colon. During the procedure, the doctor is able to remove abnormal growths like polyp in the colon.
Colonoscopy aids the doctor to remove most polyps without abdominal surgery.
Colonoscopy is more accurate than a routine x ray to detect polyps, tumors, ulcers and cancers at early stage.
Colonoscopy is done most often to investigate and find the cause of blood in the stool, abdominal pain and diarrhea.
Certain patients with previous history of polyps or colon cancer, patients with family history of particular malignancies, colon problems are advised to have periodic colonoscopies because they are at greater risk of polyps or colon cancer.
Virtual colonoscopy: Here the technique that is adopted uses a CAT scan to construct virtual images of the colon. These images are similar to the views of the colon obtained by direct observation through colonoscopy. However, virtual colonoscopy cannot find small polyps which are less than 5 mm in size. These can be seen by the traditional colonoscopy. Virtual colonoscopy is not as accurate as colonoscopy in finding cancers or pre-malignant lesions that are not protruding. Virtual colonoscopy also cannot remove polyps.
Abdominal CAT scan
CAT scans are particularly used to study with clarity several organs in the abdominal regions of the body namely liver, spleen, pancreas and kidneys. Many causes of abdominal pain are diagnosed using specialized CT equipments for interpreting CT scans of the lower gastrointestinal (GI) tract, the colon and the rectum. Abscess in the abdomen, inflammation of the colon or colon cancer, diverticulitis and appendicitis are diagnosed. When severe pain is caused by an infection or inflammation, the speed, ease and accuracy of a CT examination can reduce the risk of serious complications caused by a burst appendix or an erupted diverticulum and the subsequent spread of the infection. Especially in cases of bowel obstruction, CT is the best imaging test recommended.
Colorectal Cancer
The colon and rectum are continuous and cancers affecting them are referred to as colorectal cancers. Rectal cancer causes nearly 50,000 deaths a year in the U.S alone. Nearly 2/3 of colorectal cancers occur in the colon while about 1/2 occur in the rectum. In fact, colorectal cancers are the third-leading cause for cancer deaths in the U.S. after lung cancer and breast cancer. Typically colon cancer starts as small adenomatous polyps that later turn cancerous. Incidence of colorectal cancer is higher in Western nations as compared to Asian and African countries. More men tend to get affected by this form of cancer than women. Often heriditary syndromes cause multiple polyps in the digestive tract. Environmental and genetic factors play a large role in the occurence of colorectal cancers. Those suffering from inflammatory bowel disease or ulcerative colitis have an increased risk of developing colorectal cancers.
Rectal cancers do not produce symptoms in the initial stages. They can be detected only by digital or proctoscopic screening tests. If you notice blood in your stools or change in the shape of the stools or cramping pain in the lower abdomen, visit a doctor to check for signs of colorectal cancer. Patients may notice change in bowel habits and urinary symptoms. Stools may be narrower and often black and tarry. A feeling of bloating or colic pain may be experienced on account of obstruction due to tumor. Sometimes there is bowel perforation accompanied by fever and pain. Weight loss, fatigue and anemia may result.
A digital rectal examination helps in detecting abnormal lesions. Any tumor can be assesed for size and ulceration. Laboratory tests and screening procedures such as x-rays and endoscopy aid in visualizing the lining of the colon. Since the risk of colorectal cancer increases with age, the American Cancer Society recommends yearly digital examination of the rectum for those above 50 years. Any abnormal lesions in the rectum are examined and a biopsy is performed. If a diagnosis of rectal cancer is established, staging has to be establshed to determine the depth of tumor penetration. Staging aids the physician in determining the treatment options. Rectal cancers are divided into 4 stages. In the first 2 stages and suspected stage 3 state, surgery is used to remove the affected part of the rectum along with its vascular and lymph. Radiation and chemotherapy are also resorted to. Radiation therapy helps in shrinking the tumor prior to srugery. Rectal cancer is often linked to diets rich in fat and calories and low in fiber. Colon cancers can be prevented with the right diet and lifestyle. Diets rich in unsaturated animal fats and highly saturated vegetable oils are known to cause colorectal cancers. High-fiber food helps in the formation of soft and bulky stools, diluting carcinogens and decreasing colonic transit time. This allows lesser chance for polyps to develop. Other dietary elements such as calcium, selenium, carotenoids and vitamins A, C and E help in detroying dangerous free radicals in the colon.
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