Blind Loop Syndrome

Understand blind loop syndrome

Blind loop syndrome (or stagnant loop syndrome) happens when part of the small intestine makes a loop of tissue which food cannot pass through during the digestive process. The loop of tissue may be very small or much larger, depending on the cause. This 'blind loop' results in a reservoir of stagnating food that remains trapped in the small intestine.

In a normal small intestine the food that you eat mixes with digestive juices, and the nutrients are then absorbed into the bloodstream for onward transmission around the body.

The normal small intestine has very little bacteria, but in blind loop syndrome food trapped in the bypassed small intestine provides the perfect environment in which bacteria can proliferate. Once established, the bacteria produce toxins and prevent the efficient absorption of nutrients.

What causes blind loop syndrome?

There are a number of causes of blind loop syndrome including:

People born with a structural defect to the small intestine may also be at risk of developing blind loop syndrome in later life.

Symptoms of blind loop syndrome

There are a number of symptoms that are indicative of blind loop syndrome, including:

  • abdominal pain
  • poor appetite
  • nausea
  • bloating or feeling uncomfortably full following a meal
  • diarrhea
  • unexpected, rapid weight loss

If you experience all or any of these symptoms, you should seek medical advice immediately.

Diagnosis of blind loop syndrome

If your doctor suspects that you are suffering from blind loop syndrome, you will be referred to a gastrointestinal specialist in the hospital. You will undergo a number of diagnostic tests including:

  • X-rays and CT scans of your abdomen
  • Barium X-rays
  • CT enterography

These tests are designed to identify any abnormal physiology within the small intestine.

Further tests are usually carried out to determine the presence of bacteria within the small intestine, including:

  • hydrogen breath test
  • D-xylose breath test
  • bile acid breath test
  • fecal fat test
  • small intestine fluid culture test

Based on the result of these tests a definitive diagnosis may be made and suitable treatment commenced.

How is blind loop syndrome treated?

Blind loop syndrome is usually treated by addressing the underlying problem, i.e. removing or repairing the blind loop, stricture or fistula that is causing the issue. In cases where this is not possible treatment focuses instead on eliminating bacterial overgrowth and correcting nutritional deficiencies.

Most people with blind loop syndrome are prescribed a short course of antibiotics to control the bacterial overgrowth that is responsible for their symptoms. Obviously, the bacteria will eventually return once the antibiotics are stopped so blind loop sufferers may need regular courses in order to keep things under control.

Your doctor will probably change your antibiotics regularly to prevent bacterial resistance. You may experience some side effects from certain drugs, including diarrhea and switching to different drugs can help to avoid this problem.

An extremely important part of treating blind loop syndrome is the correction of nutritional deficiencies, especially in those suffering from severe weight loss and malnutrition.

This is normally achieved through the prescription of supplements including:

  • vitamin B-12
  • calcium
  • iron

In addition, a lactose-free diet is often recommended. This is because the small intestine cannot efficiently digest lactose (milk sugar) if it is damaged. With the exception of pro-biotic yogurt, which can be beneficial in controlling gut bacteria, dairy products and any foods containing lactose should be avoided.

Triglycerides are dietary fats, and most consist of long-chain fat molecules that can be difficult to digest. The inclusion of medium-chain triglycerides in the diet can aid digestion. Coconut oil is a good source of medium-chain triglycerides and they can also be taken as a dietary supplement.

With correct dietary management and drug therapy, blind loop syndrome sufferers can lead a normal life, even without surgery.

In conclusion

Blind loop syndrome can cause very unpleasant side-effects that can impact on your quality of life. However, the condition can be controlled and even corrected through surgical intervention or routine drug therapy and dietary changes as outlined above.

Last Reviewed:
June 30, 2017
Last Updated:
April 17, 2018