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 Colonoscopy 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.
An inflammation of the inner lining of the colon is colitis. Colitis is an inflammation in the colon and can be associated with diarrhea which could be due to infection, loss of blood supply to the colon, inflammatory bowel disease and invasion of the colon wall with lymphocytic white blood cells or collagen. While the many causes of colitis may be self-limiting and can be treated with diet and observation, nevertheless it is important to find why the inflammation had occurred as there can be more serious causes.
In case of ulcerative colitis, the exact cause remains unknown and previous diet and stress are suspected. However, doctors opine that these causes may aggravate but not cause ulcerative colitis. One possible reason could be immune system malfunction. An abnormal immune response can cause the immune system to attack the cells in the digestive tract and thereby cause malfunction. Heredity can also play a role in ulcerative colitis and it is more common in those who have a family history of the disease.
The most common bacteria that can cause colitis are Campylobacter, Shigella, E. coli, Yersinia, and Salmonella. Most of the time infections occur as the patient has eaten contaminated food. Hence the symptoms of diarrhea with or without blood, abdominal cramps, dehydration from loss of water.
Yet another bacteria that can cause colitis is Clostridium difficile. While C.diff which is found in the colon of a healthy individual co-exists with other normal bacteria, when antibiotics are prescribed, the susceptible bacteria in the colon can be destroyed and this allows clostridia to grow unchecked, and thereby cause colitis. Unfortunately, these bacteria are also found in many surfaces in the hospitals, and hence can be contagious from person to person.
In fact, worldwide the most common parasite infection that can cause colitis is Entamoeba histolytica. This is acquired by drinking infected water and can also be passed on from one to another because of poor hygienic and sanitation conditions.
Microscopic colitis can infiltrate the wall of the colon, as a result of inflammation and this is an uncommon illness and could be an auto-immune disease. In this case, the diarrhea is watery and no blood is present in the feces. In infants younger than a year, colitis is often due to allergies to cow and soy milk. Allergic colitis can also be seen in breast fed babies, where the mother drinks cow's milk and passes that protein into their breast milk.
Ulcerative Colitis can be severe depending upon its location, reading from the signs and symptoms. Depending upon which part of the colon is inflamed it could cause diarrhea, abdominal cramps, rectal pain, rectal bleeding, urgency to defecate, inability to defecate despite urgency, weight loss and fatigue, fever and failure to grow in children.
Diagnosis of Colitis
To confirm the diagnosis, the doctor may prescribe the following tests and procedures:
- Blood tests for anemia and to check signs of infection.
- A stool sample to help rule out other disorders such as infections caused by bacteria, viruses and parasites.
- Colonoscopy to view the entire colon. The doctor can take a small biopsy during the procedure for laboratory analysis. A tissue sample can help confirm the diagnosis.
- Flexible Sigmoidoscopy to examine the last portion of the colon and if it is severely inflamed, the doctor can perform this test instead of colonoscopy.
- X rays of abdominal area to rule out serious complications, such as a perforated colon.
There are several categories of drugs depending upon the severity of the condition. The drugs may work well for some but not for all. Also, drugs can cause serious side effects which can far overweigh the benefits of the treatment.
Anti-inflammatory drugs are the first step in the treatment of inflammatory bowel disease. Aminosalicylates, and Corticosteroids and immune system suppressors are prescribed. These are given orally, intravenously or by enema depending upon the location that is affected. Corticosteroids can have several side effects including puffy face, excessive facial hair, insomnia and hyperactivity and more serious ones such as hypertension, diabetes, osteoporosis, bone fractures and cataracts. These are not usually prescribed for long term.
While immune system suppressors can reduce inflammation, they do so by suppressing the immune system and therefore start the process of inflammation. A combination of drugs works better is most cases. Other medications include antibiotics, anti-diarrheal medications, pain relievers and iron supplements.
Surgery can eliminate ulcerative colitis by removing the entire colon and rectum. This procedure called ileoanal anastomosis eliminates the need to wear a bag to collect the stool. The surgeon constructs a pouch from the end of the small intestine. This pouch is then attached directly to the anus allowing expulsion of waste relatively normally. When a pouch is not possible, the surgeon creates a permanent opening in the abdomen, through which the stool is passed for collection into an attached bag.
Complications of colitis
It is recommended to have more frequent screening for colon cancer because of increased risk although it will depend on the location and duration of the disease. Some complications that can occur:
- Severe bleeding
- Perforated colon
- Severe dehydration
- Liver disease
- Inflammation of joints, skin, joints of eyes, and sores in the lining of mouth
- Increased risk of colon cancer
- Swelling colon
- Increased blood clots in veins and arteries.
Physicians who specialize in the diagnosis and treatment of the digestive system or gastrointestinal tract are gastroenterologists. When they specialize to treat children in the same area, they are termed as pediatric gastroenterologist. They treat conditions such hepatitis, colon or rectal cancer, ulcerative colitis and Crohn's disease. A gastroenterologist must complete four years of degree, four years of medical school, three years residency in internal medicines and later specialize in gastroenterology for a period of two to three years. Certification from a recognized board is necessary.
Role of gastroenterologist
- Diagnose and offer medical treatment for any kind of disorder in the gastrointestinal tract.
- Order for blood tests, x-rays, endoscope checks of the stomach called gastroscopy or for the large intestine called colonoscopy depending on the patient's illness.
- Assist a surgeon in exactly locating the area of problem that needs treatment in the gastrointestinal section.
- They follow up digestive system disorders that include esophagus, small and large intestine, stomach, pancreas and the liver. They also follow up on symptoms of heartburn, indigestion, ulcers etc following an operation.
Modern techniques and gastroenterologist
- Use of ultra high frequency in endosonography gives better understanding of any lesions formed.
- Measuring of myoelectric and contractile activity in the gastrointestinal tract, esophageal and anal manometry to understand constipation, nausea, abdominal pain etc better in any patient.
- Electrogastrography and few other modern techniques have made it easier to understand the esophageal transit in patients easier.