Health Information

Blind loop syndrome

Blind loop syndrome


Stasis syndrome; Stagnant loop syndrome

Blind loop syndrome occurs when digested food slows or stops moving through part of the intestines. This causes an overgrowth of bacteria in the intestines. It also leads to problems absorbing nutrients.

I Would Like to Learn About:

  • Causes

    The name of this condition refers to the "blind loop" formed by part of the intestine that is bypassed. This blockage does not allow digested food to flow normally through the intestinal tract.

    The substances needed to digest fats (called bile salts) do not work as they should when a section of the intestine is affected by blind loop syndrome. This prevents fat and fat-soluble vitamins from being absorbed into the body. It also leads to fatty stools. Vitamin B12 deficiency may occur because the extra bacteria that form in the blind loop use up this vitamin.

    Blind loop syndrome is a complication that occurs:

    • After many operations, including subtotal gastrectomy (surgical removal of part of the stomach) and operations for extreme obesity
    • As a complication of inflammatory bowel disease

    Diseases such as diabetes or scleroderma may slow down movement in a segment of the intestine, leading to blind loop syndrome.

  • Symptoms

    • Diarrhea
    • Fatty stools
    • Fullness after a meal
    • Loss of appetite
    • Nausea
    • Unintentional weight loss
  • Exams and Tests

    During a physical exam, the doctor may notice a mass in, or swelling of, the abdomen. Possible tests include:

    • Abdominal CT scan
    • Abdominal x-ray
    • Blood tests to check nutritional status
    • Upper GI series with small bowel follow through contrast x-ray
  • Treatment

    Treatment most often starts with antibiotics for the excess bacteria growth, along with vitamin B12 supplements. If antibiotics are not effective, surgery may be needed to help food flow through the intestines.

  • Outlook (Prognosis)

    Many people get better with antibiotics. If surgical repair is needed, the outcome is often very good.

  • Possible Complications

    • Complete intestinal obstruction
    • Death of intestine (intestinal infarction)
    • Hole (perforation) in intestine
    • Malabsorption and malnutrition
  • When to Contact a Medical Professional

    Call your health care provider if you have symptoms of blind loop syndrome.

Related Information

  BileVitamin B12GastrectomyCrohn's diseaseSclerodermaBacterial gastroen...Intestinal obstruc...     VitaminsCrohn diseaseScleroderma


Semrad CE. Approach to the patient with diarrhea and malabsorption. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 142.


Review Date: 2/11/2014  

Reviewed By: Todd Eisner, MD, Private practice specializing in Gastroenterology, Boca Raton, FL. Affiliate Assistant Professor, Florida Atlantic University School of Medicine. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.


A.D.A.M. content is best viewed in IE9 or above, Firefox and Google Chrome browser.