Skip to Content
Home > Health Information > Health Library > Small Intestine
The small intestine is a winding, tightly folded tube about 20 ft (6 m) long in adults. It connects to the stomach on the top end and to the large intestine (colon) on the bottom end. Most of the food a person consumes is digested and absorbed in the small intestine. The lining of the small intestine has tiny, finger-shaped tissues (villi). These raised tissues greatly increase the surface area of the intestine, which absorbs calories and nutrients from food.
The small intestine consists of three parts. The first part, called the duodenum, connects to the stomach. The middle part is the jejunum. The third part, called the ileum, attaches to the colon.
Current as of: November 7, 2018
Author: Healthwise StaffE. Gregory Thompson, MD - Internal MedicineAdam Husney, MD - Family Medicine
Current as of:
November 7, 2018
Medical Review:E. Gregory Thompson, MD - Internal Medicine & Adam Husney, MD - Family Medicine
To learn more about Healthwise, visit Healthwise.org.
© 1995-2019 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.
Our interactive Decision Points guide you through making key health decisions by combining medical information with your personal information.
You'll find Decision Points to help you answer questions about:
Get started learning more about your health!
Our Interactive Tools can help you make smart decisions for a healthier life. You'll find personal calculators and tools for health and fitness, lifestyle checkups, and pregnancy.
Feeling under the weather?
Use our interactive symptom checker to evaluate your symptoms and determine appropriate action or treatment.
See important information from Billings Clinic on Non-discrimination and Interpreter Services.
Billings Clinic is proud to be an equal opportunity/affirmative action (EOE/AA) e-verify employer.