Blind Loop Syndrome

Blind loop syndrome, also called stagnant loop syndrome or stasis syndrome, happens when a portion of the small intestine creates a loop that food bypasses during the digestive process. This results in food not being able to move through the digestive tract normally. When food and waste products move through the digestive system slowly, bacterial overgrowth can occur, leading to complications. Sometimes the underlying cause of the condition can be fixed. When this isn’t’ possible, the condition can typically be successfully managed.


Symptoms of blind loop syndrome include unintentional weight loss, feeling uncomfortably full after eating, nausea, loss of appetite, diarrhea, bloating, and abdominal pain.


The small intestine is the longest part of the digestive tract. Food is mixed with digestive juices and nutrients are absorbed in the small intestine. The small intestine doesn’t typically host a lot of bacteria. However, in blind loop syndrome, slowly-moving or stagnant food act as a breeding ground for bacterial overgrowth. Not only can this bacteria produce toxins, it can also inhibit the absorption of nutrients.

Several things can trigger blind loop syndrome, such as gastrectomy for stomach cancer or ulcers or gastric bypass surgery for obesity and structural issues in or around the small intestine, such as scar tissue or diverticulosis. Certain medical conditions, such as diabetes, celiac disease, Crohn’s disease, scleroderma, obesity, and radiation enteritis can also slow the movement of waste products and food through the small intestine, triggering the symptoms of blind loop syndrome.


When bacteria is present in the small intestine, it breaks down the bile salts necessary to digest fats. Consequently, the body cannot absorb the fat-soluble vitamins A, D, E, and K, which may lead to vitamin deficiencies. Bacteria present in the small intestine also absorb vitamin B12, which can lead to a vitamin B12 deficiency. Severe vitamin B12 deficiency can cause you to feel fatigued, weak, and experience numbness and tingling in your hands and feet. In advanced cases, you may also experience mental confusion.

Abnormal bacterial overgrowth in the small intestine also results in poor calcium absorption, which can lead to osteoporosis. Kidney stones may also occur as a result of poor calcium absorption. Finally, toxins are released when bacteria break down slow-moving or stagnant food. These toxins harm the small intestine’s mucus lining, leading to poor absorption of most nutrients, including proteins and carbohydrates. Malnourishment may occur as a result.

Diagnosis and Treatment

Imaging tests, such as an abdominal CT or an abdominal x-ray are typically utilized in the diagnosis of blind loop syndrome. Other tests may be used to check for bacterial overgrowth in the small intestine, vitamin deficiencies, and poor fat absorption.

The underlying cause of blind loop syndrome is treated whenever it’s possible. This involves surgically repairing the structural abnormality. When repairing the loop isn’t possible, doctors treat bacterial overgrowth with courses of antibiotics and nutritional deficiencies with supplements.

If you are experiencing the symptoms of blind loop syndrome, visit your doctor. Your doctor will be able to make a diagnosis and guide you through the treatment process.