Intestinal failure is a condition where the small intestine cannot absorb enough nutrients and fluids to sustain the body’s needs. When this occurs, individuals often require alternative support, such as intravenous nutrition delivered directly into the bloodstream, known as parenteral nutrition. This complex medical state can arise from various underlying issues that impair the intestine’s ability to function properly.
Causes Due to Reduced Intestinal Length or Damage
A common reason for intestinal failure is a significant reduction in the functional length of the small intestine, a condition frequently referred to as short bowel syndrome. This often happens after surgical removal of a large portion of the small intestine, which may be necessary due to various diseases or injuries. For instance, Crohn’s disease, a chronic inflammatory condition, can lead to extensive damage and necessitate surgical removal of affected intestinal segments.
Mesenteric ischemia, a condition where blood flow to the intestine is decreased or blocked, can also cause severe damage leading to the need for surgical resection. If the blood supply is significantly compromised, parts of the intestine can die, requiring their removal. Another cause, particularly in infants, is necrotizing enterocolitis (NEC), where intestinal tissue becomes inflamed and dies, often necessitating surgery to remove the damaged sections. Trauma or conditions like volvulus, where the intestine twists and cuts off its own blood supply, can also result in extensive damage and surgical intervention.
Causes Due to Impaired Intestinal Movement
Intestinal failure can also stem from disorders that disrupt the muscular contractions of the intestine, even if the organ’s structure appears normal. These conditions, known as motility disorders, prevent food and fluids from moving effectively through the digestive tract. Chronic intestinal pseudo-obstruction (CIPO) is one such disorder where the intestine behaves as if it is blocked, despite no physical obstruction being present.
In CIPO, problems with the nerves or muscles of the gastrointestinal tract prevent synchronized contractions. CIPO can be primary, meaning its cause is unknown or genetic, or secondary, resulting from other conditions like scleroderma, certain neurological conditions, or even some medications. In scleroderma, a condition causing excessive tissue hardening, the gut muscles can weaken, leading to significant motility issues and sometimes CIPO.
Causes Due to Severe Malabsorption
Sometimes, intestinal failure occurs even when the intestine is of adequate length and has normal movement, but its inner lining is severely dysfunctional. This means the cells responsible for absorbing nutrients are damaged or do not work correctly. Severe forms of enteropathies, which are diseases affecting the small intestine, can cause widespread damage to this mucosal lining.
Microvillus inclusion disease (MVID) is a rare genetic enteropathy that severely impairs nutrient absorption. In MVID, the surface cells lining the intestine do not develop properly, leading to chronic, watery diarrhea and the inability to absorb essential nutrients. Other genetic disorders can also cause specific transporter functions to fail.
Congenital Conditions Leading to Intestinal Failure
Intestinal failure can also be present from birth due to various congenital conditions. These are distinct from conditions acquired later in life and often involve structural abnormalities of the intestine. Gastroschisis is a birth defect where the intestines protrude outside the baby’s body through a hole in the abdominal wall. This exposure to amniotic fluid can damage the intestines, leading to complications like inflammation, shortening, or twisting, which may necessitate surgical removal of damaged sections and potentially result in short bowel syndrome.
Omphalocele is another abdominal wall defect where organs, including the intestines, protrude through the umbilical cord but are covered by a protective sac. While the sac offers some protection, severe cases can still lead to organ damage or smaller abdominal capacity, requiring complex surgical management. Hirschsprung’s disease, a condition where nerve cells are missing in parts of the colon, can also lead to intestinal failure, particularly if a long segment of the bowel is affected.