What is intestinal adaptation?
Intestinal adaptation is the process in which the intestinal tract adjusts after significant loss of bowel, for example after resection of the intestine (surgery to remove part of the small bowel). The changes occur immediately after the bowel is removed, but the full process may take months to years. In most cases, intestinal adaptation happens within two to three years. Children are believed to be better able to adapt compared to adults as a child's bowel naturally has more potential to grow.
During adaptation, the way the bowel functions changes. These changes include:
- slowing down motility (how quickly food passes through)
- changes in bowel length and thickness to improve absorption
These changes help the bowel start to absorb nutrients and fluids more effectively.
Intestinal adaptation is a natural process that can be enhanced by providing enteral nutrition (food by mouth or tube) even at a very small amount.
Enteral autonomy (EA)
In children with intestinal failure, the goal of intestinal adaptation is to achieve enteral autonomy. This means receiving all calories, fluid and nutrients via the GI tract and stopping all parenteral nutrition (PN). Enteral autonomy can be achieved using oral feeds (feeding by mouth) or using a tube such as a nasogastric tube (NG) or an enterostomy tube (G or GJ tube).
Children who have more remaining small bowel after surgery are more likely to come off PN and achieve EA. The amount of small bowel remaining after surgery is the most significant but not the only predictor of achieving EA. Other predictors include:
- how well the bowel moves
- intact ileocecal valve (a passageway between the small and large bowel)
- primary diagnosis
- colon length
- function of the liver
- number of infections your child has had
Strategies to enhance intestinal adaptation and enteral autonomy
It is important to take a multidisciplinary approach to help your child achieve enteral autonomy and to enhance intestinal adaptation These strategies include:
Nutrition
Feeding the bowel with nutrients prevents the intestinal mucosa (the inner lining of the intestinal tract) from decreasing in size. For this reason, it is important to introduce feeding shortly after surgery. The type of food is also important to the adaptive process. Children with intestinal failure require ongoing dietary management.
Feeding strategies to promote eating by mouth can also help in the adaptation process. These feeding strategies include encouraging bottle feeding if your child is safe to have feeds by mouth and starting solids as soon as your child is developmentally ready to do so. Oral feeding stimulates secretions and releases hormones that can help with adaptation. It can also prevent oral aversion (not wanting to eat or allow anything to touch the mouth) that can delay further introductions of solid food, and speech and language development.
Medication
The most common medications used include medications to:
- help thicken stools
- aid in motility
- prevent gastroesophageal reflux disease (GERD)
- prevent line infections
- treat small bowel bacterial overgrowth
Hormones such as Glucagon-like peptide-2 (GLP-2) play an important role in intestinal function. These hormones have been shown to increase digestion, absorption and blood flow in the bowel, which all contribute to intestinal adaptation. In recent years, new drug therapies using GLP-2 hormones have been shown to be effective in helping some patients with short bowel syndrome wean PN and reach enteral autonomy.
Surgery
Aside from the primary surgery, surgical intervention may be needed to help achieve faster and more efficient intestinal adaptation in some children. Often, children will need additional procedures to optimize bowel function. Your child’s health-care team will discuss surgical options with you if your child needs additional surgeries.