Short-Bowel Syndrome

Short bowel syndrome is a serious condition that occurs when the body cannot absorb enough nutrients and fluids from food because part of the small intestine is missing or damaged. This rare disorder affects how your body processes the food you eat and requires specialized care to manage.

Table of contents

• What is short bowel syndrome?
• What causes short bowel syndrome?
• Signs and symptoms
• How is it diagnosed?
• Treatment approaches
• Managing daily life with short bowel syndrome
• Possible complications
• Associated anatomy

What is short bowel syndrome?

Short bowel syndrome is a condition in which the body cannot absorb enough nutrients from foods because part of the small intestine is missing or damaged^[1]. This serious and chronic disorder happens when your intestines cannot work properly to break down and absorb the food you eat^[4].

The small intestine is where most of the nutrients you eat are absorbed into your body during digestion. In adults, the normal length of the small intestine ranges from 275 to 850 centimeters^[2]. When someone has less than 180 to 200 centimeters of remaining small bowel, they may develop short bowel syndrome and need nutritional and fluid supplements^[2].

About 75% of cases develop after a single, massive removal of bowel, while the remaining 25% occur after multiple removals^[2]. Short bowel syndrome is rare, affecting an estimated 10,000 to 20,000 people in the United States^[3][5].

short gut syndrome, short gut, intestinal failure

What causes short bowel syndrome?

Short bowel syndrome can happen when parts of the small intestine have been surgically removed or when portions of the small intestine are missing or damaged at birth^[1]. The condition results from either the physical or functional loss of the intestines, usually the small intestine^[4].

In adults, the most common conditions that lead to short bowel syndrome include^[1][4]:

• Crohn’s disease (a type of inflammatory bowel disease that causes inflammation in the digestive tract)
• Mesenteric ischemia (loss of blood flow to the intestines)
• Traumatic injuries to the small bowel
• Blood clots in the arteries that provide blood to the intestines
• Cancer
• Volvulus (twisting of the intestine)
• Radiation enteritis
• Post-surgical adhesions and complications

In children, the causes are often different from adults. Short bowel syndrome in children most often develops from conditions present at birth that lead to removal of the intestine^[4]:

• Necrotizing enterocolitis (the most common cause in premature infants, when the lining of the intestinal wall dies)
• Gastroschisis (abdominal wall defects where intestines develop outside the body before birth)
• Intestinal atresia (a blockage or missing section in the intestine)
• Twisting of the intestine (volvulus)
• Hirschsprung’s disease (missing nerve cells in the intestine)
• Other birth defects

Some babies may be born with a short small intestine or with a damaged small intestine that must be surgically removed^[1].

Signs and symptoms

When a person has short bowel syndrome, their body has a hard time absorbing all the nutrients and fluids it needs to function normally^[5]. The most common symptoms include^[1][3][5]:

• Diarrhea or loose, watery stool
• Greasy, foul-smelling stools
• Fatigue or sleep problems
• Weight loss or difficulty maintaining weight
• Malnutrition (not getting enough nutrients from food)
• Swelling in the legs and feet
• Bloating
• Excessive gas
• Stomach pain and cramping
• Heartburn
• Vomiting

In infants and children, loose, watery stool or diarrhea are the most common symptoms. Poor growth can also be a sign of short bowel syndrome in children^[3].

The condition puts people at risk for several serious problems^[4][5]:

• Dehydration, which can show up as dark-colored urine, infrequent urination, muscle cramping, or excessive thirst
• Nutrient deficiency, which can cause weight loss or the inability to maintain weight
• Imbalances of electrolytes (important minerals like sodium and potassium), which can cause muscle weakness
• High output from an ostomy (a surgical opening), typically more than eight cups of fluid in a 24-hour period

In children, nutrient deficiencies can cause growth and developmental delays^[4].

How is it diagnosed?

To diagnose short bowel syndrome, a healthcare professional may recommend blood or stool tests to measure nutrient levels^[9]. Your doctor will evaluate your medical history and the status of your digestive system to determine the best path forward^[5].

They may ask about your symptoms, such as diarrhea, dehydration, and weight loss. They may also perform a blood test to see if you are lacking basic nutrients^[5]. Your doctor will also assess your unique nutritional needs to provide the support you require to supplement your diet^[5].

Other tests may include imaging procedures, such as an X-ray with a contrast material, CT scan, MRI, or CT or MRI enterography (special imaging that can show blockages or changes to the intestines)^[9].

There are multiple factors a doctor may use to determine a short bowel syndrome diagnosis, not just the length of remaining bowel^[5]. Important factors include the length of small bowel remaining, which segment of intestine was lost, the age of the patient at the time of bowel loss, and the presence or absence of the ileocecal valve (a valve between the small and large intestine)^[6].

Treatment approaches

Treatment options for short bowel syndrome depend on what parts of the small intestine are affected, whether the colon is intact, and a person’s own preferences^[9]. The main goals of treatment are to make sure you get enough nutrients, prevent complications, and reduce your need for parenteral nutrition (nutrients delivered through a vein)^[10].

Nutritional support

The main treatment for short bowel syndrome is nutrition support^[10]. People with short bowel syndrome will need to follow a special diet and take nutritional supplements^[9]. The type and amount of nutrition support you need may depend on what stage your short bowel syndrome is in and how severe it is^[10].

Some people may need to receive nutrition through a vein (parenteral nutrition) or a feeding tube (enteral nutrition) to prevent malnutrition^[1][9]. Although parenteral support helps maintain essential nutrients and hydration, it does not help your remaining intestine absorb nutrients, which is an important treatment goal^[4].

Receiving enteral nutrition or eating and drinking can help your intestines heal^[10]. For infants and young children, eating and drinking as soon as they are able to may prevent problems with eating and drinking later in life^[10].

Medicines

In addition to nutritional support, medicines may be recommended to help manage short bowel syndrome^[9]. These include:

• Medicines to help control stomach acid
• Medicines to reduce diarrhea
• Medicines to improve intestinal absorption after surgery
• Antibiotics, if needed
• Growth hormone and other medications to enhance bowel adaptation

Surgery

Types of surgery to treat short bowel syndrome include procedures to slow the passage of nutrients through the intestine or a procedure to lengthen the intestine, called autologous gastrointestinal reconstruction^[9]. Small bowel transplantation may also be an option for some patients^[9].

Intestinal adaptation

After bowel removal surgery, the lining of the remaining intestine may change to absorb more nutrients and fluid through a natural process called intestinal adaptation^[5]. This is an important goal for people with short bowel syndrome. In adults, the adaptation stage lasts about two years, while in children it may last longer^[10].

How well your remaining intestines adapt may depend on how much of the small intestine you have and how healthy it is, which parts were removed, and whether part or all of the colon remains^[10].

Managing daily life with short bowel syndrome

Managing short bowel syndrome usually includes a combination of strategies and is adjusted to a person’s individual needs^[11]. Primary aims include maintaining essential nutrition and hydration, improving intestinal adaptation, reducing or eliminating long-term parenteral support, and improving daily life^[11].

Diet considerations

There is no single “short bowel syndrome diet.” Depending on the portion and length of your remaining bowel and how well it functions, your doctor may help create a diet tailored to you^[11]. Different parts of the digestive tract absorb specific nutrients, so your diet will depend on your particular surgery^[11].

If you have any remaining colon, you may need to maintain a diet that is low in fat and high in carbohydrates. If you have a jejunostomy or ileostomy, you may need to maintain a diet that is high in fat, low in carbohydrates, and higher in salt^[11].

Unless otherwise instructed by your doctor, you should generally eat small and frequent meals to help manage certain symptoms and encourage digestion and absorption^[11]. You will probably need to consume a lot more food and calories than someone with a normal-sized bowel to compensate for your bowel’s inability to absorb nutrients normally^[11].

One of the most important dietary recommendations is to avoid sweets. Candy, fruit juices, and sodas are high in simple sugars, which pull water into the gastrointestinal tract and lead to fluid and nutrient loss^[19]. Complex carbohydrates are the best types of carbs to eat, as they are more easily digested and absorbed^[19].

Staying hydrated

Dehydration can be a serious concern. However, battling dehydration isn’t simply a matter of drinking more water. In fact, this can make the problem worse by increasing diarrhea or ostomy output^[11].

Oral rehydration solution (ORS) is a specific solution of salt, sugar, and water that is used to aid in dehydration. The special ratio of ingredients enhances absorption of fluid across the small bowel wall^[11]. You may be asked to drink about 1000 milliliters of a glucose/salt solution per day and restrict other fluids to around 1000 milliliters a day^[17].

When it comes to maintaining hydration, remember to sip fluids slowly throughout the day. Drinking fast does not allow the intestine time to absorb the fluid^[11]. Drink fluids between meals instead of with meals^[17].

Working with your healthcare team

Managing short bowel syndrome requires a dedicated team approach. Your healthcare team may use a combination of approaches including diet, surgery, tube feeding, medications, and intravenous nutrition and hydration^[11]. A registered dietitian can help make sure you get enough nutrients^[10].

Possible complications

A variety of complications can occur in patients with short bowel syndrome^[13]. These include chronic diarrhea, weight loss related to poor absorption, fluid and electrolyte disturbances, vitamin and mineral deficiencies, nephrolithiasis (kidney stones), and liver and kidney diseases^[13].

These complications are often associated with a loss of intestinal surface area for absorption and rapid intestinal movement triggered by the underlying disease, altered bowel structure, or treatments such as parenteral nutrition^[13].

Persons with short bowel syndrome may have complications caused by poor absorption of vitamins and minerals, such as deficiencies in vitamins A, D, E, K, B9 (folic acid), and B12, calcium, magnesium, iron, and zinc^[7]. These may appear as anemia, scaling of the skin, easy bruising, muscle spasms, or poor blood clotting^[7].

For children with short bowel syndrome, long-term concerns can include nutrient deficiencies affecting bone health and growth, so regular monitoring is important even after they no longer need tube feedings^[22].

Associated anatomy

• Small intestine
• Duodenum
• Jejunum
• Ileum
• Large intestine (colon)
• Ileocecal valve