Short Bowel Syndrome Causes, Signs, Symptoms, Diagnosis, Treatment, Prevention

Short Bowel Syndrome Causes, Symptoms, Diagnosis, Treatment, Prevention


What Is Short Bowel Syndrome?


Short bowel syndrome means a child’s small bowel (small intestine) isn’t long enough and doesn’t work well enough to absorb the nutrients they need from the food they eat.

During digestion, muscles in the small bowel squeeze to push food along. As the food travels through the bowel, it comes in contact with the thin lining (mucosa) inside the bowel. Nutrients - like carbohydrates, protein, fat, vitamins and minerals - get absorbed through this lining as part of normal digestion.

There must be plenty of contact between the food and lining of the bowel to absorb enough nutrients. A healthy small bowel has more than enough length to digest food and absorb nutrients. So removal of small segments (portions) of the bowel usually does not cause problems. But if the bowel is too short, such as after removal (resection) of a large segment, there is not enough contact for good absorption.

This is why Short Bowel Syndrome can cause malnutrition and serious problems with growth and development. Without treatment, Short Bowel Syndrome can be deadly.

The small intestine fails to absorb food nutrients properly


Normally, absorption of food nutrients happens in the small intestine. Food is squeezed from the stomach, through a sphincter (valve) and into the first part of the small intestine (duodenum), where it is mixed with digestive enzymes. Next, muscular contractions (peristalsis) massage the food into the lower parts of the small intestine (jejunum and ileum). 

Nutrients are absorbed along the length of the small intestine, which is lined with millions of microscopic, finger-like projections called villi. Each villus is connected to a mesh of capillaries so that nutrients can pass into the bloodstream. Short bowel syndrome refers to the malabsorption of food nutrients due to failure of the small intestine. 

What causes short bowel syndrome?


The main cause of short bowel syndrome is surgical removal of half or more of the small intestine to treat intestinal diseases, injuries, or defects present at birth.

In newborns, short bowel syndrome may occur following surgery to treat conditions such as:
  • necrotizing enterocolitis, a condition that occurs in premature infants and leads to the death of bowel tissue
  • congenital defects of the bowel, such as midgut volvulus, omphalocele and gastroschisis, jejunoileal atresia, internal hernia, and congenital short bowel
  • meconium ileus, a condition associated with cystic fibrosis
In children and adults, short bowel syndrome may occur following surgery to treat conditions such as:
  • intussusception, a condition in which part of the intestine folds into another part of the intestine
  • bowel injury from loss of blood flow due to a blocked blood vessel
  • bowel injury from trauma
  • cancer and damage to the bowel caused by cancer treatment
Short bowel syndrome can also be caused by disease or injury that prevents the small intestine from functioning as it should despite a normal length.

Short Bowel Syndrome Risks


A risk factor is something that increases your chance of getting a disease or condition.

The following factors are thought to increase the risk of short bowel syndrome:

  • Crohn's Disease (the most common reason for the removal of the small intestine)
  • Vascular problems
  • Premature Birth

What are the signs and symptoms of short bowel syndrome?


Diarrhea is the main symptom of short bowel syndrome. Diarrhea can lead to dehydration, malnutrition, and weight loss. These problems can be severe and can cause death without proper treatment.

Other symptoms may include
  • cramping
  • bloating
  • heartburn
  • weakness and fatigue
Specific nutrient deficiencies may occur depending on what sections of the small intestine were removed or are not functioning properly. Sites of nutrient absorption in the small intestine are:
  • the duodenum, the first section of the small intestine, where iron is absorbed
  • the jejunum, the middle section of the small intestine, where carbohydrates, proteins, fat, and vitamins are absorbed
  • the ileum, the last section of the small intestine, where bile acids and vitamin B12 are absorbed.
People with short bowel syndrome are also at risk for developing food sensitivities.

Diagnosis for Short Bowel Syndrome


If a person has had major bowel surgery and a significant length of small intestine has been removed, they may experience symptoms such as severe diarrhoea and weight loss. These symptoms may indicate that the person has short bowel syndrome. This condition can improve in time, once intestinal adaptation takes place. 

Some of the tests to confirm the diagnosis of short bowel syndrome may include:
  • Blood tests
  • Stool (poo) examinations
  • X-rays
  • Intestinal biopsies.

Short Bowel Syndrome Treatment


The main treatment for short bowel syndrome is nutritional support. Treatment may involve use of oral rehydration solutions, parenteral nutrition, enteral nutrition, and medications. Oral rehydration solutions consist of sugar and salt liquids. Parenteral nutrition delivers fluids, electrolytes, and liquid nutrients into the bloodstream intravenously - through a tube placed in a vein. Enteral nutrition delivers liquid food to the stomach or small intestine through a feeding tube.

Feeding


Children with short bowel syndrome cannot absorb enough nutrients from the food they eat by mouth. They need other ways to get the nutrients their bodies need.

Many children with Short Bowel Syndromeneed to be fed through a tube that goes into a vein (intravenous, or IV, feeding). 

This is called parenteral nutrition (PN). For some children, PN is a long-term treatment. But PN can lead to liver problems and bacterial infections. So doctors often work to wean children off PN if they can.

If we can get a child’s small bowel working again (restore function) by using diet, medicine and, in some cases, surgery, we may be able to wean them off PN. Weaning involves slowly adding some feedings by mouth or directly into the stomach while gradually lowering the amount of nutrition provided through the IV. To wean off PN, we may use these kinds of feeding tubes (enteral nutrition):
  • Nasogastric tube, which goes from their nose into their stomach
  • Gastrostomy, which goes through the skin of their abdomen (belly area) and into their stomach
  • Jejunostomy, which goes through the skin of their abdomen and into their small bowel
For infants and young children with Short Bowel Syndrome, another important part of feeding is giving your child some food by mouth. This helps your child learn how to suck and eat. Even if they can’t absorb what they eat by mouth now, they need to learn these skills early so they are able to eat by mouth later in life. Your child’s healthcare team will make this part of your child’s care plan.

Intestinal rehabilitation


“Intestinal rehabilitation” is the process of trying to get your child’s small bowel working again (restore function) by using diet, medicines and, in some cases, surgery. This is a main focus of our Intestinal Care Program for children with Short Bowel Syndrome or other types of intestinal failure.

Diet

PN delivers all of the nutrients a child needs straight into the child’s bloodstream. But it means food does not pass through the child’s small bowel. Having some food pass through the bowel may help the bowel begin to work better. So treatment for Short Bowel Syndrome often means striking a balance - using PN while giving some food by mouth or directly into the stomach, if possible. Your child’s healthcare team will create a plan for your child to try giving food by mouth slowly over time.

Medicines

Medicines are used in children with Short Bowel Syndrome to:
  • Lower the acid from the stomach
  • Slow the movement of food through the bowel
  • Decrease diarrhea
  • Help them absorb more nutrients
  • Control bacteria in the bowel
Hormones may be used to promote growth of the bowel lining (mucosa), which helps it absorb more nutrients.

Surgery

Surgery may be used in children with Short Bowel Syndrome to taper or to lengthen the small bowel.

In children with Short Bowel Syndrome, a segment of the small bowel may enlarge (dilate). Fluid and bacteria can collect in this area. This can lead to infections and can keep nutrients from being absorbed. So surgeons may operate to make this area smaller. This is called intestinal tapering.

Some children with Short Bowel Syndrome have enough small bowel that surgeons can lengthen it and restore function. The surgery we use is called STEP (serial transverse enteroplasty). The surgeon cuts notches in both sides of an enlarged segment of bowel and sews along the cut edges. The notches dovetail into each other, like the teeth of a zipper. This creates a zig-zag-shaped bowel. It’s narrower and longer than the bowel was before the surgery. This means that food will take longer to move through the bowel and will come into contact with the bowel lining for a longer period. This allows the child’s body to digest food better and create less stool.

Transplant

If intestinal rehabilitation does not help your child enough, or if it’s not an option for your child, then an intestine transplant may be the next step.

Seattle Children’s has the only program in the Pacific Northwest and one of the few nationwide with specialists who can perform intestine transplants. If your child needs a transplant, our team will support you and your family throughout the process.

Points to Remember

  • Short bowel syndrome is a group of problems related to poor absorption of nutrients that typically occurs in people who have had half or more of their small intestine removed.
  • People with short bowel syndrome cannot absorb enough water, vitamins, and other nutrients from food to sustain life.
  • Diarrhea is the main symptom of short bowel syndrome and can lead to dehydration, malnutrition, and weight loss.
  • Treatment may involve use of oral rehydration solutions, parenteral nutrition, enteral nutrition, and medications. Having an intestinal transplant may be an option for some patients. 
  • Researchers are studying ways to help the small intestine that remains after surgery adapt and function better.

How to Prevent Short Bowel Syndrome


There is no known way to prevent short bowel syndrome.