Living and Wellness What Do Intestines Do for the Body? By Digestive Disorders, September 6, 2015 Ever wonder how all that food you eat turns into the energy you use every day? You might not think about your intestines very often, but they’re probably at work right now, helping your body absorb needed nutrients. Your intestines are the main organs that absorb essential nutrients from the foods you eat. Broken up into the small intestine and the large intestine, both have very important roles in how your body works. Below, you’ll find information about these organs that will help you understand their important roles. What Is the Small Intestine? The longer of your two intestines, your small intestine is between twenty and thirty feet long and absorbs most of your food. There are three major sections of your small intestine which include: Duodenum: Mixes semi-digested food with bile from your gallbladder, liver, and pancreas to break down food further Jejunum: Absorbs fatty acids, sugars, and amino acids Ileum: Absorbs most of the nutrients before passing food along to the large intestine What Is the Large Intestine? After passing through your small intestine, food then moves to the large intestine. Around five feet long, the large intestine absorbs salts and liquid left over from the digestive process. Most nutrients are already absorbed by the time food enters your large intestine. Some substances are left over, including: Fiber Plant material (which is hard to digest) Dead cells Water Bile pigments After passing through the colon for reabsorption, these substances exit your body in the form of waste through your anus. Common intestinal diseases and conditions Your intestines have the largest surface area in your body, around 250 square meters, which allows your body to achieve maximum food absorption. Many diseases can affect your intestines, causing painful symptoms, like diarrhea, fever and fatigue, abdominal pain, cramping, weight loss and reduced appetite, and more. Some of these disorders include: Inflammatory bowel disease, which is comprised of Crohn’s disease and ulcerative colitis Colon polyps and colorectal cancer Functional bowel disorders, including constipation and irritable bowel syndrome (IBS) Diverticular disease Short gut syndrome Medical or surgical treatment of intestinal failure While many intestinal diseases and conditions can be treated with medicines, lifestyle changes, and other therapies, some diseases may require an intestinal transplant. In the transplant, the diseased section of intestine is removed and replaced with a healthy donor’s intestine. Although it is considered a major surgery, many patients are able to restore their normal diet. Your transplant team will talk with you about of all the risks and benefits of the surgery. UPMC intestinal transplant teams offer a multidisciplinary approach making sure all aspects of your care are treated. For more information or to make an appointment please call 412-647-5800 or visit the UPMC Transplant Services website.