What is blind loop syndrome?

Your digestive system breaks down the food you eat so your body can use it for fuel. Food moves from your stomach into your intestines. There, nutrients are absorbed. The excess food is pushed into the colon and leaves the body as waste.

In blind loop syndrome, food is not able to follow the normal digestive route. Instead, it bypasses a section of your intestine.

Blind loop syndrome is also called:

• Stasis syndrome
• Stagnant loop syndrome
• Bowel bypass syndrome.

What causes blind loop syndrome?

Blind loop syndrome is often due to an overgrowth of bacteria in the intestine. This forces food to route around it. Because of the "blind loop" that is formed, the small intestine is shorter than normal. The intestines can’t properly absorb nutrients. They are instead passed out of your body in waste.

Blind loop syndrome often occurs as a complication of abdominal surgery. The most common type of surgery that causes this is bowel-shortening surgery for obesity. In this surgery, part of the intestine is purposely bypassed.

Digestive problems may also trigger blind loop syndrome. It may occur as a complication of:

• Diverticulitis
• Peptic ulcer disease
• Inflammatory bowel disease (Crohn's disease and colitis)

What are the symptoms of blind loop syndrome?

One of the main symptoms of blind loop syndrome is unexplained weight loss. This occurs when your whole intestine can't digest food and absorb nutrients. When your body isn’t getting the nutrients and fat it needs, weight loss occurs.

When bacteria overgrowth occurs in your intestines, bacteria are also carried through the bloodstream and body. This bacterial infection can cause:

• Fever
• Arthritis-like joint pain
• Skin rash or red bumps on the skin
• Inflamed tendons
• Pain or achiness in muscles

Poor absorption of nutrients and poor nutrition can cause a number of symptoms, such as:

• Frequent diarrhea
• Nausea or vomiting
• Swelling in the abdomen from a buildup of fluid
• Pain and cramping in the abdomen
• Stools that seem loose and fatty
• Fatigue or weakness
• Gas and bloating

How is blind loop syndrome diagnosed?

Your healthcare provider will ask about your symptoms, your medical, surgical, and family history. He or she will request tests to test for nutrient absorption, anemia, or to rule out other conditions. Tests may include:

• Blood tests to check for infections and nutrition status
• Breath tests to look for bacterial overgrowth
• Tests to check organ function
• Test to check for inflammation in the body
• Exam of stool for fecal fat, stool culture, parasites, white blood cells

How is blind loop syndrome treated?

Healthcare providers can treat blind loop syndrome. You will likely take antibiotics. A short course of corticosteroids to reduce inflammation may also help control symptoms.

Sometimes you need surgery to remove the infected area. If obesity surgery caused blind loop syndrome, your surgeon may do another operation to correct the problem.

What are the complications of blind loop syndrome?

If left untreated blind loop syndrome may lead to poor nutrition.  However, even early on, blind loop syndrome can cause a lack of vitamins and minerals, including Vitamin B₁₂ and iron.

When should I call my healthcare provider?

If you notice any symptoms of blind loop syndrome, it is important to tell your healthcare provider. Be aware of the condition if you’ve had abdominal surgery or have a digestive disease such as inflammatory bowel disease. Blind loop syndrome can be treated, but if nutrients can’t be absorbed, it can cause serious health problems.

Key points

• Blind loop syndrome occurs when food doesn't follow the normal digestion route and bypasses a section of your intestine.
• It can be caused by abdominal surgery, diverticulitis, inflammatory bowel disease, peptic ulcer disease, or an infection.
• One of the main symptoms of blind loop syndrome is unexplained weight loss.
• Other symptoms include fever and infection-type symptoms, and diarrhea, vomiting, and abdominal pain and swelling.
• Blind loop syndrome is usually treated with antibiotics. Surgery may also be needed.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

• Before your visit, write down questions you want answered.
• Bring someone with you to help you ask questions and remember what your provider tells you.
• At the visit, write down the names of new medicines, treatments, or tests, and any new instructions your provider gives you.
• If you have a follow-up appointment, write down the date, time, and purpose for that visit.
• Know how you can contact your provider if you have questions.