Table of ContentsView AllTable of ContentsAnatomyFunctionAssociated ConditionsTestsFAQ
Table of ContentsView All
View All
Table of Contents
Anatomy
Function
Associated Conditions
Tests
FAQ
The colon is part of thelarge intestine, and it has several different sections: ascending, transverse,descending, andsigmoid. The ascending colon is the first section. It is located in the digestive tract between the end of the small intestine and the second part of the colon, the transverse colon. It is also sometimes called the right colon.
In this article, learn more about the anatomy and function of the ascending colon, as well as conditions that can affect it and tests that may be done.
The colon is part of the digestive tract, where food is broken down into substances that the body can use. The ascending colon is the first section of the colon. It receives partially digested food from thesmall intestine.
Structure
The ascending colon is about 8 inches (20-25 centimeters) long and 2.5 inches in diameter.The inside of the ascending colon is lined with smooth muscles that contract and move stool along its length.
The innermost layer of the ascending colon is called the mucosa. It has goblet cells, which help create the mucus needed to help waste move along the length of the colon.
The next layers are the sub-mucosa, which contains nerves and blood vessels, and the muscularis, which contains smooth muscle. The outermost layer is the serosa, which secretes a fluid to reduce friction from smooth muscle contraction.
Location
The ascending colon is located on the right side of the abdomen. It receives the digesting food from the small intestine. At its start, it is connected to the cecum, which is the first part of the large intestine.
At its end, the ascending colon makes a left turn where it meets the second part of the colon, the transverse colon. The transverse colon goes from right to left across the abdomen.
Anatomical Variations
Variations and birth defects in the ascending colon are not common. Malrotations of the colon, where the intestine becomes twisted, are usually discovered in newborns because they often cause digestive symptoms.Surgery is used to correct the problem.
There are some variations in the branching of the arteries that supply blood to the parts of the colon. The artery that supplies the right colon is thesuperior mesenteric artery. There have been rare case reports of the blood supply instead coming from the inferior mesenteric artery.
The colon is a hollow tube, and waste material (stool) passes through it on its way out of the body through the anus. The purpose of the colon is to absorb water and electrolytes from the stool. Most vitamins and minerals are absorbed in the small intestine.
When the waste passes from the small intestine and into the cecum, it is mixed with various types of bacteria. This bacteria further breaks down the waste and helps the absorption of a few more vitamins, such as vitamins K, B1, B2, and B12.
Water is absorbed from the waste material as it passes through the colon, turning it from mostly liquid into solid stool.
Colon Cancer
Colon cancercan begin in the ascending colon. Because it doesn’t always cause symptoms, it is often not found until the cancer is advanced.
Colon Cancer: What Determines Success of Treatment?
Colon Polyps
Colon polypsare stalk-like growths that occur on the inner intestinal wall. They protrude into the interior of the colon. If they become large, they can block waste material from passing through.
Certain types of polyps are the precursor to cancer. During a screening colonoscopy, any polyps that are found will be removed so that they do not continue to grow and present a risk of cancer.
Diverticular Disease
Diverticular diseaseis a condition in which outpouchings develop in weakened sections of the lining of the colon. It’s common for people over the age of 40 to have these pouches in the colon lining, and most people over the age of 50 have them.
They may not cause any symptoms unless they become infected, which is called diverticulitis. Diverticulitis may cause fever, nausea, abdominal pain, and diarrhea. Diverticulitis is most often treated with antibiotics, but severe cases may need surgery.
What’s the Difference Between Diverticulitis and Diverticulosis?
Inflammatory Bowel Disease
Crohn’s disease,ulcerative colitis, andindeterminate colitisare forms ofinflammatory bowel disease (IBD)that can affect the ascending colon. IBD causes inflammation and ulcers in the digestive tract. This can lead to signs and symptoms in the digestive tract, such asintestinal bleeding, abdominal pain, and diarrhea.
Further, IBD can cause extra-intestinal complications that include fatigue, skin conditions, eye problems, and various forms of arthritis.
IBD is usually treated with medications such as anti-inflammatory drugs and/or corticosteroids. In some cases, surgery may be necessary.
Tests that are used to assess the health of the entire colon will include assessment of the ascending colon.
Colonoscopy
Colonoscopyis a test in which a thin, flexible tube with a light is inserted into the rectum and moved up through the length of the colon. This test is done under anesthesia. The preparation for this test includes cleaning the colon of any stool, which is done using strong laxatives and fasting.
How Often Should You Get a Colonoscopy?
Computed Tomography
Computed tomography (CT)is used to look at the organs in the abdomen. It is a type of X-ray that can create an image of the colon and other body structures. This test can show, for instance, if there are any tumors in the colon.
Magnetic Resonance Imaging
Magnetic resonance imaging (MRI)uses a magnetic field to see the structures and organs inside the body. It may be done with or without contrast. Contrast for MRI is administered through an IV. No radiation is used in this test.
Positron Emission Tomography
Positron emission tomography (PET)is used to find tumors. Sugar treated with a low level of radiation is given through an IV before the test. If any tumor cells are present, they will take up this sugar and show up on films taken during the test.
Summary
The ascending colon is the first part of the large intestine. It receives partially digested food from the small intestine and absorbs the water and electrolytes.
Frequently Asked Questions
The ascending colon is on the right side of the abdomen. It begins at the cecum, the first part of the large intestine. The ascending colon turns left and meets the transverse colon, which goes across the abdomen.
Yes. Large bowel resection surgery (colectomy) is a procedure to remove all or part of a damaged or diseased colon.Once a portion of the colon is removed, if there is enough healthy intestine left, the ends are stitched together, known as anastomosis.If there is not enough large intestine to reconnect, a hole (stoma) will be made through the abdomen and stool will drain into a colostomy bag outside the body.
Yes. Large bowel resection surgery (colectomy) is a procedure to remove all or part of a damaged or diseased colon.
Once a portion of the colon is removed, if there is enough healthy intestine left, the ends are stitched together, known as anastomosis.
If there is not enough large intestine to reconnect, a hole (stoma) will be made through the abdomen and stool will drain into a colostomy bag outside the body.
4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
National Cancer Institute.Anatomy of the colon and rectum.
Nemours KidsHealth.Intestinal malrotation.
Abe T, Ujiie A, Taguchi Y, et al.Anomalous inferior mesenteric artery supplying the ascending, transverse, descending, and sigmoid colons.Anat Sci Int. 2018;93:144-148. doi:10.1007/s12565-017-0401-2.
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