Colon

The colon is a component of the digestive system. It is the part of the large intestine between the cecum and the rectum, which primarily extracts moisture from undigested food before they are excreted. The colon is made up of three different sections: the transcending colon, ascending colon, and descending colon. As food is digested and converted into waste, it passes through the small intestine first where nutrients are extracted and then passed along to the colon before going out through the rectum. The colon also extracts nutrients from your food into the bloodstream via the walls of the large intestine, while at the same time excreting stool down to the rectum.

Anatomy

The colon is around 4 to 6 feet in length and 2 ¹/₂ inches in width. It can best be described as a muscular tube that is responsible for the absorption of water and the removal of stool. The outer layer of the colon is callous, made of circular muscles that help move the waste down the tube and into the rectum. In between the outer and inner layers of the colon is a mucus encoated layer that holds lymphatic tissue, blood vessels, and connective tissue. Just beneath this is the inner layer, which is the primary source for transferring blood to the colon (which is extremely sensitive and humid). This overview of the large intestine can be broken down into six different divisions: the transverse colon, ascending colon, appendix, descending colon, sigmoid colon, and the rectum.

Divisions of the Colon To start with, the mouth of the colon is made in part by the ileocecal valve and the cecum valve. These valves, found between the small and large intestine, provide for the transfer of substances that have been broken down in the small intestine into the colon. They begin the journey into the transverse, ascending, and descending colons. These organ parts all work together to play a significant role in the digestive system. Their smooth muscles make it possible for the efficient movement of waste throughout the colon. They also generate alkaline mucus, secreted from the colon walls, to continue the flow of digestion. One thing that will make these sections easier to remember is that their names are derived from the position in the body where are located. The ascending colon is located along the right side of the body and forces waste up into it. It requires that smooth muscles work against gravity in order for waste to travel smoothly. Next, the waste will move into the transverse colon which runs right across the body, then into the descending colon which runs downwards, before finally converting into the sigmoid colon. From there, it follows into the rectum.

The rectum is classified as a deposit for stool until the time comes for it to be extracted. When the time comes to remove waste, elastic receptors within the rectum are stimulated. This notifies the person that a bowel movement is expected, but the action is not enacted until the one in control chooses. Once it gets past, its last stop is the anus, which is made up of soft tissues, elastic membranes, and other muscles and nerves that can stretch for any size of bowel movements. This is why constipation can hinder your anus' ability to function properly; the repairs might be costly. There are many factors that contribute to a person's ability to produce a bowel movement normally like how well the "tone" of the rectum works and if one's skeletal muscles are working correctly. Generally, an individual should make about one to two bowel movements per day. Anything lower can be a sign of danger.

Diseases

Diseased colon with Ulcerative Colitis after surgery

The most common of colonic diseases is Colon Cancer, or Colorectal Cancer. Studies show that it is the fourth most common disease in men and women over the age of 50. The risk can increase with age or if one has these variables: malign polyps, a diet high in fat, a family history or personal history of Colorectal Cancer, or Ulcerative colitis or Crohn's disease. There are symptoms that can present themselves when Colon Cancer is a possible scenario for the patient. People over 50 should know how to recognize these signs of cancer. Any blood found within the waste or any noticeable changes with their bowel movements should be reported to a trusted physician and/or hospital. Keeping your health in check is also the routine screening process of colonoscopy.

Colonoscopy is a medical screening process that allows for the doctor to see up into the colon and rectum. It is intended to show signs of cancer, ulcers, and malignant growths of polyps within the colon. It serves to explain any unnatural occurrences with bowel movements, and pain in the abdomen or anus. Doctors will prepare the patients for a colonoscopy by giving them written instructions. They advise the patient not to eat any solids for a 1 to 3 day period before the screening so they can empty out their intestine tract normally. The patient lives on a liquid diet, staying away from drinks with red or purple coloring. It is also common to be given a laxative, to loosen the stool, the night before a colonoscopy. The following is a list of drinks that is recommended to the patient for daily use before a colonoscopy:

• fat-free bouillon or broth
• strained fruit juice
• water
• plain coffee
• plain tea
• sports drinks, such as Gatorade
• gelatin

During a colonoscopy, the patient will be asked to lie still on their left side. The doctor will insert a long, flexible tube equipped with a light and a small camera into the patient's anus, through the rectum and into the colon. There he will fill the colon with carbon dioxide to increase the view size of the camera, playing a video of the procedure on a screen nearby. The screening process is over once the tube reaches the lining of where the small intestine meets the large intestine.

Scars after a surgery from Ulcerative Colitis

Ulcerative Colitis

Ulcerative Colitis is a type of disease of inflammatory bowel disease. It causes ulcers to form where inflammation has killed cells within the lining of the colon and rectum. This disease can hit between the ages of 15 and 30, especially if it is genetic or hereditary. Signs of Ulcerative Colitis may include but are not limited by weight loss, bleeding in rectum or anus, pain in the abdomen, sores on the skin, and pain in the joints. These symptoms can be dangerous, but only around half of Colitis patients receive mild cases of them. So it is useful to take any medication the doctor prescribes to control the disease. If the patient’s condition worsens, the colon must be removed before any more harm can be done to the body.

Polyps

Polyps are growths that reside within the colon or large intestine. The majority of polyps are benign and have no harming effects to the body, but some can take on a cancerous nature over time. The doctor can determine the state in which the polyps are in by removing some through a colonoscopy and examining them. The risk of getting malign polyps in the colon is measured by these facts: if the patient is over 50 years old, has had cancerous polyps before, a family medical history with polyps/colon cancer, or if they are men. They don’t usually cause symptoms to occur, but can be noticed if there is blood residue on underwear, blood in your poop, and chronic constipation or diarrhea.

External Links

• Colon Polyps National Digestive Diseases Information Clearing House- NDDIC.
• Anatomic Problems of the Colon National Digestive Diseases Information Clearing House- NDDIC.
• Large Intestine InnerBody.
• Colonoscopy National Digestive Diseases Information Clearing House- NDDIC.
• Anatomy and Physiology of the Colon The Colon Cleansing & Constipation Resource Center- C. Olon
• What is the function of your Colon and what does it do to keep you healthy? Cheryl Ashby, C.C.T.
• Colonic Diseases Medline Plus.