Congenital Abnormalities of the Gastrointestinal Tract - Causes, Types, Symptoms, Diagnosis, and Treatment

Introduction:

The congenital malformation of the gastrointestinal tract results in abnormal function of the digestive system. It is rarely diagnosed among infants with or without life-threatening situations. Therefore, the favorable prognosis depends on early diagnosis and management, including surgical correction.

What Are Congenital Abnormalities of the Gastrointestinal Tract (GIT)?

It is a condition that results in an abnormal digestive system due to developmental defects or vascular accidents of the fetus with disruption of the blood flow, often resulting in vomiting and feeding difficulties in the first two days of extrauterine life (after birth). The abnormalities are divided into upper and lower gut defects based on structural and functional defects. In most cases, structural defects impair the function of GIT.

What Causes Congenital Abnormalities of the Gastrointestinal Tract (GIT)?

Congenital abnormalities of GIT occur due to the embryonic underdevelopment of the fetus (the baby within the womb). Although the underlying cause is unknown, some studies show a genetic correlation with GIT anomalies.

What Are the Types of Congenital Abnormalities of GIT?

Abnormalities are broadly classified into upper and lower gastrointestinal disorders and further classified into three types based on an embryonic defect of the foregut, mid, and hindgut.

• Foregut Disorder: The foregut is the ligament that gives rise to the esophagus, stomach, duodenum, biliary ducts, liver, and pancreas. Hence, it results in atresia (complete blockage of GIT) and stenosis (partial blockage of GIT) of the esophagus, duodenum, and biliary duct.

• Midgut and Hindgut Disorder: The mid and hindgut give rise to the jejunum, ileum, cecum, colon, anal, and rectum. Hence results in malformation of the bowel, colon, and anorectal (anal and rectal).

What Are the Typical Abnormalities of GIT?

The typical defects of GIT involve atresia, stenosis, malrotation, and volvulus.

• Esophageal Atresia: The narrow esophagus results in drooling in infants with feeding difficulties. In some cases, pneumonia is noticed in the later period of life. The most common symptoms are coughing, choking, and regurgitation.

• Duodenal Atresia: The obstruction of the duodenum leads to bilious (bile color or yellowish green vomit) and non-bilious emesis (vomit without color code).

• Pyloric Stenosis: The obstruction of the pylorus (part of the stomach that connects to the duodenum) results in feeding intolerance followed by vomit presenting around two to four weeks of life. White-skinned Europeans have more chances of getting pyloric stenosis.

• Biliary Atresia: The inflammation of the biliary duct results in jaundice with signs of dark urine and light or gray-colored stools.

• Small Intestine Atresia: It is characterized by a structural obstruction that disrupts the meconium (first stool of an infant) in the first two days of life and results in bilious emesis.

• Malrotation and Midgut Volvulus: During development, the digestive tract rotates to its final position. A defect with rotation leads to malrotation. It is commonly seen in the small intestine with or without symptoms. The volvulus is the condition where the loop of the intestine twists around, resulting in bowel obstruction and ischemia.

• Hirschsprung’s Disease: The total absence of ganglion cells or nerve cells in the muscle or large intestine results in meconium obstruction for 24 hours of life, followed by diarrhea due to rectal stimulation. It is also known as aganglionosis and is rarely diagnosed in children (two to three years of age) with severe constipation.

• Abdominal Wall Defects: The obstruction of the abdominal wall leads to the development of the gastrointestinal tract outside the body.

• Tracheoesophageal Fistula (TEF): It is a condition characterized by an inflammatory connection between the esophagus and the trachea (windpipe). TEF may also occur in adulthood due to cancer, infection, or trauma.

• Anorectal Malformation: The malformation of the anal and rectal results in abdominal distention (bloating or swelling in the belly area) and absence of the anus. Predominantly associated with anoperineal fistula (the infectious connection between the skin and anus) and rectourethral fistula (release of first stool during urination).

What Are the Symptoms of Gastrointestinal Tract Malformation?

Symptoms vary from one child to another based on severity, defect, and location.

The common symptoms are:

• Constipation.

• Cough.

• Feeding difficulties.

• Jaundice (yellow disease).

• Abdominal distention (swollen abdomen).

• Vomiting.

• Fatigue.

• Diarrhea (seen with Hirschsprung's disease).

What Are the Life-Threatening Conditions?

The malrotation followed by volvulus has a higher incidence of a life-threatening condition. The symptom involves:

• Abdominal pain.

• Bloody stools.

• Constipation.

• Diarrhea.

• Abnormal breathing pattern.

• Increased heart rate.

• Rectal bleeding.

• Bloating abdomen.

• Bilious emesis (yellowish-green vomit).

• Failure to thrive (decreased body weight).

• Draw up a knee or leg (bend one's legs and move one's knees toward one's chest).

What Is the Diagnosis of Abnormal GIT?

The diagnosis can be made at both prenatal and natal stages. The diagnostic methods are listed below:

• Prenatal Ultrasound: The sound waves are generated to produce the digital image of an organ which aids in diagnosing gastrointestinal tract anomalies at the prenatal stage (before birth).

• Biopsy: Golden standard for diagnosis of Hirschsprung's disease.

• Blood Investigations: Blood samples are collected to rule out electrolytes, an essential factor of gastrointestinal defects.

• Stool Samples: It is used for the evaluation of blood and other bile products within the stool.

• Sigmoidoscopy: A flexible sigmoidoscopy is a process by which a flexible tube is inserted into the large intestine through the rectum. It is used to evaluate the lower part of the large intestine (colon).

• Other Tests: Computed tomography (CT scan) and MRI (magnetic resonance imaging) are standardized imagining non-invasive (painless) techniques with excellent soft tissue contrast to provide useful information, and X-rays using barium produce a detailed image of the digestive tract and abdomen that helps in the evaluation of abnormalities.

What Are the Treatment Methods for Congenital Abnormalities of GIT?

Significantly, surgical correction is used for the majority of gastrointestinal conditions with the guideline of accessing the defect, repairing the obstruction, aligning the organs, and then suturing the incision. Open surgery is performed to assess and repair severe defects. In contrast, laparoscopy (accessing the defective site through the anus or rectum) is indicated to repair minor defects.

What Are the Drawbacks After the Treatment?

The favorable outcomes depend on the severity of the defects. Some degree of lifestyle modification is required to manage constipation (enema). And long-term parenteral nutrition is indicated for children with poor absorption of nutrients-long-term follow-up with a gastroenterologist and nutritionist.

Conclusion:

Congenital abnormalities of the gastrointestinal tract have a higher incidence of mortality (death rate) and morbidity (disease rate) among children. Occasionally, it goes undiagnosed during childhood and may occur during adolescence.