Table of ContentsView AllTable of ContentsThe IntestinesNormal Intestine FunctionConditionsTestsLiving With Chronic Symptoms
Table of ContentsView All
View All
Table of Contents
The Intestines
Normal Intestine Function
Conditions
Tests
Living With Chronic Symptoms
The large and small intestines are part of thegastrointestinal (GI) tract, the passage running from the mouth to the anus. The intestines run from the end of the stomach to the anus. Their primary function is to absorb nutrients and vitamins.
Thesmall intestineis made up of three parts—theduodenum(first part), thejejunum(middle part), and theileum(end part).
Though thecolonand the large intestine are occasionally mistaken for one another, they are not the same organ. The colon is one part of the large intestine, which also contains theappendix, the cecum, and the rectum, with the colon connecting to the cecum and rectum.
This article will cover the location and function of the intestines, abnormal function, diagnosing and treating problems, and more.
Where Are the Intestines in the Body?
The small intestine is located in the lower quadrant of the abdomen.The large intestine wraps around the border of the abdominal cavity on the right side of the body, extends to the top of the abdomen, and then down the left side. Theileocecal sphincterconnects the large intestine to the ileum of the small intestine.
What Is the Ileocecal Sphincter?The ileocecal sphincter, also called the ileocecal valve, is an involuntary valve located where the small intestine and large intestine meet.It is involuntary in that it operates without conscious control.Valves in the human body work to keep the movement of fluids going in one direction. The ileocecal sphincter contracts to limit the reflux (backflow) of colonic substances to the small intestine.
What Is the Ileocecal Sphincter?
The ileocecal sphincter, also called the ileocecal valve, is an involuntary valve located where the small intestine and large intestine meet.It is involuntary in that it operates without conscious control.Valves in the human body work to keep the movement of fluids going in one direction. The ileocecal sphincter contracts to limit the reflux (backflow) of colonic substances to the small intestine.
The ileocecal sphincter, also called the ileocecal valve, is an involuntary valve located where the small intestine and large intestine meet.It is involuntary in that it operates without conscious control.
Valves in the human body work to keep the movement of fluids going in one direction. The ileocecal sphincter contracts to limit the reflux (backflow) of colonic substances to the small intestine.
The Small Intestine
The small intestine connects the stomach to the large intestine. It is the longest part of the digestive system, measuring between 10 and 16 feet.It is up to or more than twice the length of the large intestine.
The different sections of the small intestine have different lengths.The ileum is the longest section, while the duodenum is the shortest.
The small intestine is called “small” because of its 1-inch width.Despite its small size, it is covered in various folds and ridges, which allow for better absorption of nutrients and fluids.
The Large Intestine
The large intestine runs from the small intestine to the anus. It is around 5 feet long.The colon is the largest part of the large intestine. The other parts are much shorter, only a few inches in length.
The large intestine has a larger width than the small intestine.It is around 3 inches wide.
Your Digestive System and How It Works
Your intestines are an essential part of your digestive system. Food sources are broken down into their component nutrients, vitamins, and minerals, which are then absorbed.Waste products are then concentrated for elimination in the stool.
The intestines work to give your body nourishment and energy to keep it healthy and for it to function correctly.
The majority of absorption occurs in the small intestine.Digested foods can pass into the blood vessel walls of the small intestine via a process called diffusion. Examples of nutrients absorbed in the small intestine are carbohydrates, proteins, lipids (fats), vitamins, iron, and water.
The small intestine’s three parts assist with absorption and digestion.
Whatever is left over during the absorption process moves to the large intestine.
The primary function of the large intestine is to finish the absorption of nutrients and water that starts in the small intestine.It also works to form, store, and eliminate fecal (waste) matter from the body.
Each of the parts of the large intestine has its part to play.
A Look Inside Your Digestive System
Conditions and Abnormal Intestine Function
Various health conditions may affect the intestines. Symptoms of an intestinal problem may include:
Symptoms of an intestinal problem will come and go. If you experience any of these symptoms regularly or have severe pain, make an appointment with your healthcare provider. They can determine the cause of symptoms and recommend treatments.
Conditions that may affect the intestines include:
Types of Dysmotility and Motility Disorders
Tests to Reveal Intestine Dysfunction
Various problems of the intestines can affect food digestion and absorption. Diagnosing these problems is vital to getting effective treatment and preventing complications. Depending on your symptoms, your healthcare provider will employ different lab tests and imaging to confirm a diagnosis.
Lab Tests
Lab tests your healthcare provider may utilize in making a diagnosis include:
Imaging
Imaging tests to diagnose intestinal problems include:
Living With Chronic Intestinal Symptoms
After you determine the cause of your intestinal symptoms, you should work with your healthcare provider to create an individualized treatment plan. Living with intestinal conditions can be challenging, but treating and managing your condition successfully and maintaining a good quality of life are possible.
Many of these conditions can affect how you feel about yourself because of how your body functions. Living with these conditions also means managing medication side effects, disease symptoms, and diet changes.
Some of these triggers, like diet, stress, nonsteroidal anti-inflammatory drug (NSAID) use, and smoking, can be managed, and it is possible to reduce the number of flares you experience. Your healthcare provider can also recommend a treatment course ofcorticosteroidsto help you manage and heal from an IBD flare more quickly
Gastroparesis Diet: What to Eat and What to Avoid
Some intestinal conditions require surgery to treat symptoms, reduce problems and complications, and remove obstructions. For example, some people with Crohn’s disease may needcolostomysurgery to remove a portion of the intestine and create an opening in the abdominal wall called a stoma. Anostomy bagcollects fecal matter from the stoma.
A colostomy procedure might be necessary if Crohn’s affects food digestion, nutrient absorption, and the elimination of fecal waste.
A person with an ostomy bag can continue to do many of the same activities they did before the colostomy surgery. And most people are unaware if someone else has an ostomy bag. You may need to avoid lifting heavy items and take frequent bathroom visits to empty the bag. Other than that, the ostomy bag would not impact your daily routine.
Colon Cleanses
Colon cleanses can clean out the bowels quickly. A colon cleanse might be helpful for managing bloating or constipation.
A colon cleanse might also be done using supplements or laxatives. You should check with a healthcare provider before using these products, especially if you have an intestinal condition.
A last method, colonic irrigation, involves using water to flush waste material out of the bowel with a tube inserted in the rectum.A colonic hygienist performs this procedure.
Some research suggests that colon cleanses might be safe for people with IBD.Even so, it is always a good idea to check with a healthcare provider to determine whether one is safe for you based on your unique health situation.
Summary
The intestines are part of the GI tract and include both the small intestine and the large intestine. They run from the end of the stomach to the anus and work to absorb nutrients and vitamins.
Various conditions can affect the intestines, including inflammatory bowel disease, irritable bowel syndrome, diverticular disease, constipation, viral gastroenteritis, and colorectal cancer. Signs of an intestinal condition include abdominal pain, bloody stools, bloating, gas, nausea, vomiting, diarrhea, and constipation.
Intestinal conditions can be treated and managed. Outcomes are best when diagnosed and treated early. Contact a healthcare provider right away if you experience severe abdominal pain, bloody stools, or chronic digestive symptoms (e.g., bloating, gas, constipation).
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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.
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Taylor T.The large intestine. Innerbody.
National Institute of Diabetes and Digestive and Kidney Diseases.Your digestive system & how it works. December 2017.
Taylor, T.Ileocecal valve. Innerbody.
Anatomy and Physiology.The small and large intestines.
LibreTexts Medicine.22.13A: Absorption in the small intestine.
Oregon State University.23.6 The small and large intestines. 2019.
Smith HF, Parker W, Kotzé SH, Laurin M.Morphological evolution of the mammalian cecum and cecal appendix.Comptes Rendus Palevol. 2017;16(1):39-57. doi:10.1016/j.crpv.2016.06.001
National Institute of Diabetes and Digestive and Kidney Disorders.Constipation. May 2018.
John Hopkins Medicine.Lactose intolerance.
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MedlinePlus.Enteritis. May 4, 2022.
National Institute of Diabetes and Digestive and Kidney Disorders.Irritable bowel syndrome (IBS). November 2017.
Johns Hopkins Medicine.Diverticular disease.
Celiac Disease Foundation.What is celiac disease?
Centers for Disease Control and Prevention.What is inflammatory bowel disease?April 13, 2022.
American Cancer Society.Key statistics for colorectal cancer. January 29, 2024.
Johns Hopkins Medicine.Understanding an intestinal obstruction.
Johns Hopkins Medicine.Digestive diagnostic procedures.
Garber J.Living with Crohn’s disease: recognizing and managing flares. Harvard Health Publishing. December 11, 2019.
Johns Hopkins Medicine.Living with an Ostomy.
Cedars-Sinai.Ask a doc: Are colon cleanses healthy?
Restellini S, Kherad O, Bessissow T, et al.Systematic review and meta-analysis of colon cleansing preparations in patients with inflammatory bowel disease.World J Gastroenterol.2017;23(32):5994-6002. doi:10.3748/wjg.v23.i32.5994
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