Blind loop syndrome occurs when part of the intestine becomes blocked, so that digested food slows or stops moving through the intestines. This causes bacteria to overgrow in the intestines and causes problems in absorbing nutrients.

The name of this condition refers to the "blind loop" formed by the blocked intestine. This blind loop does not allow the normal flow of digested food through the intestinal tract.

When a section of the intestine is blocked by blind loop syndrome, bile salts needed to digest fats become ineffective, resulting in fatty stools and poor absorption of fat and fat-soluble vitamins. Vitamin B12 deficiency may occur because the extra bacteria that develop in this situation use up all of the vitamin.

Blind loop syndrome is a complication that occurs after many operations, including subtotal gastrectomy (surgical removal of part of the stomach), operations for extreme obesity, or as a complication of inflammatory bowel disease or scleroderma.

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

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

• Abdominal CT scan
• Abdominal x-ray
• Contrast enema study

The initial treatment generally involves antibiotics for the bacterial overgrowth, along with vitamin B12 supplementation. If antibiotics don't work, surgery to help the flow of food through the intestine may be considered.

Many patients get better with antibiotics. If surgical repair is required, the outcome is typically very good.

• Complete intestinal obstruction
• Intestinal infarction (death of intestine)
• Perforation (hole) of intestine

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