The upper gastrointestinal (GI) system includes the mouth, esophagus, and stomach. Its primary functions are to take in food and fluids, begin the digestive process, and propel food into the intestines, where nutrients are absorbed. The mouth, or buccal cavity, is the entrance to the GI tract. Here food is broken up and mixed with saliva. This process starts the digestion of carbohydrates. The submandibular, parotid, and sublingual glands secrete saliva in response to the smell, taste, or thought of food. The tongue contains taste buds that distinguish salt, sweet, sour, and bitter sensations. The tongue is essential for swallowing.

At birth, the esophagus measures approximately 10 cm in length; it lengthens to 18 to 25 cm by adulthood. The upper third of the esophagus consists of striated voluntary muscle; the lower two thirds consist of smooth muscle. The upper esophageal sphincter (UES) prevents the reflux of esophageal contents into the pharynx and lungs and prevents esophageal distention during respiration; the lower esophageal sphincter (LES, or cardiac sphincter) prevents the reflux of gastric contents into the lower esophagus.

Swallowing is under both voluntary and involuntary control. As food is chewed, it forms a small bolus, or mass; the tongue propels the bolus toward the oropharynx. The presence of this mass in the oropharynx stimulates the medulla, causing the soft palate to rise. The nasal passages close, the pharyngeal muscles contract, the larynx closes, and respiration is inhibited. As a

result of these processes, food is propelled to the esophagus. Through peristalsis, the bolus moves on to the LES, the muscle relaxes, and the bolus enters the stomach.

The stomach lies in the epigastric, umbilical and left hypochondrial regions of the abdomen. It is a muscular pouch, shaped somewhat like a gourd, where the bolus is received. As the LES and the pylorus contract, the stomach muscles churn the contents. The contents mix with the digestive juices to form chyme. The chyme moves on to the pylorus and into the duodenum.

A mucous-bicarbonate barrier in the stomach provides a thick layer of mucus and a buffer zone to neutralize acid. Stomach acids diffuse slowly through this layer toward the gastric wall. They are neutralized by bicarbonate ions from the surface epithelial cells. Thus a neutral pH is maintained at the gastric epithelial surface.

Lower Gastrointestinal System

The lower GI system includes the duodenum, liver, gallbladder, pancreas, jejunum, ileum, cecum, appendix, ascending colon, transverse colon, descending colon, sigmoid colon, rectum, and anus. The primary functions of the lower GI tract are to digest and absorb nutrients, detoxify and excrete unwanted waste, and aid in fluid and electrolyte balance.

The duodenum, the first part of the small intestine, extends from the pylorus to the jejunum. Partially digested chyme from the stomach enters the duodenum, where pancreatic enzymes and bile are excreted to further break down fats, carbohydrates, and proteins. The pancreas is an oblong gland lying behind the stomach that secretes enzymes to digest food and secretes glucagon and insulin to control motility and absorption.

The liver, the largest organ in the body, is located under the right diaphragm. The liver lies predominantly in the right upper quadrant, with the left lobe extending into the left upper quadrant. It is divided into two lobes separated by the falciform ligament. Within each lobe are numerous lobules, which form the functional units of the liver.

The liver is unique in that it is supplied with blood from two sources: (1) the hepatic artery, which supplies oxygenated blood; and (2) the hepatic portal vein, which supplies deoxygenated blood with absorbed nutrients from the GI tract. The liver has numerous functions, including phagocytosis, bile production, detoxification, glycogen storage and breakdown, and vitamin storage. The production of bile is essential for the absorption of fat and the excretion of the end products of blood cell breakdown. The primary function of the gallbladder, a saclike structure attached to the underside of the right lobe of the liver, is to store bile for secretion into the duodenum when stimulated by the presence of fat in its lumen.

The jejunum and ileum form the remainder of the small intestine. Absorption of all nutrients and vitamins occurs here through the villi and microvilli by the processes of diffusion and active transport. Absorption of vitamin B₁₂ occurs only in the terminal ileum.

The large intestine starts with the cecum. This blind pouch, 2 to 3 inches long, begins at the ileocecal valve, which prevents reverse peristalsis into the small intestine. Attached to it is the appendix, a wormlike tube about 3 inches long. The open end of the cecum attaches to the remainder of the colon, which is divided into four sections: the ascending, transverse, descending, and sigmoid colon. One major function of the large intestine is water reabsorption, which occurs mostly in the cecum and ascending colon. Intestinal bacteria ferment the remaining carbohydrates and aid in the synthesis of vitamins B and K. Final breakdown of bile occurs here. Mucus secretion and peristalsis of wastes are also important functions.

The rectum is the last 7 to 8 inches of the intestine, and the anal canal refers to the last 1 to 2 inches. Stool is stored in the rectum until distention of the rectal walls initiates the defecation reflex—the final stage of the GI processes.

Prenatal Development

The primitive gut is formed from the endoderm in the first 4 weeks of embryonic development. The primitive gut then gives

COMMON LABORATORY AND DIAGNOSTIC TESTS FOR GI DISORDERS

TEST	DESCRIPTION	NORMAL FINDINGS	INDICATIONS	PREPARATION AND NURSING CONSIDERATIONS
Stool
Culture and sensitivity	Organisms from a small sample of stool are grown in culture media.	Normal GI flora	To identify infectious organisms and determine their antibiotic sensitivity.	No patient preparation is necessary. The sample is delivered to the laboratory immediately; it must be kept free from contamination.
Reducing substances (Clinitest)	Stool is diluted with water and then tested for undigested carbohydrates with Clinitest tablets.	Negative	Used to diagnose malabsorption syndromes.	No preparation is necessary. The test is done by the nurse, who checks for a color change in the solution.
Occult blood (guaiac, Hematest)	Stool is smeared on filter paper and prepared with solution.	Negative	Used in inflammatory conditions and bowel necrosis.	No preparation is necessary. The test is done by the nurse; a blue color is positive.
Ova and parasites (O&P)	Stool is examined microscopically for presence of parasites or their eggs.	Negative	To identify enteric parasites in child with diarrhea or abdominal pain.	No patient preparation is necessary. Sample must be free from water or urine contamination. The sample is delivered to the laboratory either fresh or in preservatives. Barium, antacids, mineral oil, and antibiotics may interfere with results. 1-3 samples are collected.
Urine
Urobilinogen	Dipstick or laboratory analysis is performed to determine bile byproducts in urine.	Negative	Levels determined in hepatic dysfunction and obstruction.	No preparation is necessary. The test is done by the nurse.
Blood
Liver function tests	Serum levels are measured to give an indication of liver function.	AST: child < 9 yr, 15-55 U/L; child > 9 yr, 5-45 U/L ALT: 5-45 U/L Total bilirubin: 0.2-1.0 mg/dL Ammonia: 29-70 mcg/dL in children; 90-150 mcg/dL in newborns	Studies are performed when liver problems are suspected.	No preparation is necessary. Venipuncture is performed.
Endoscopy
Fiberoptic upper GI endoscopy	Study allows direct viewing of the lining of the esophagus, stomach, and proximal duodenum. It also provides a means to obtain material for biopsies and cultures.	Normal mucosa	Used to rule out various upper GI tract disorders.	Preparation includes teaching, keeping the child on NPO status for at least 6 hr before the examination, providing conscious sedation, and monitoring the child’s respiratory function during sedation.
Colonoscopy	The colon is viewed directly by a fiberoptic scope and camera inserted rectally.	Normal mucosa and patent bowel	Performed to detect mucosal changes and abnormalities in the lumen of the colon.	Preparation includes teaching, keeping the child on NPO status, bowel cleansing, and providing conscious sedation.
Biopsy (gastric, jejunal, rectal, liver)	A small piece of tissue is removed for analysis.	No abnormal tissue	Study determines the amount of mucosal inflammation and the absence of ganglion cells.	Preparation includes teaching, bowel cleansing, and providing sedation or anesthesia if the procedure is done percutaneously (liver).
Radiologic Examinations
Abdominal flat plate	Anterior and posterior radiographs are obtained.		Radiographs demonstrate stool and gas patterns, inflammation, and patency of the GI tract. It is commonly performed in cases of abdominal pain, imperforate anus, intussusception, and appendicitis.	Usually no preparation is necessary other than teaching.
Barium swallow examination	Radiopaque contrast medium or air (or both) is swallowed.	Normal swallowing, no anatomic defects	Study identifies esophageal abnormalities, swallowing difficulties, and sphincter function.	Preparation includes teaching and keeping the child on NPO status for 2-4 hr before the examination. Adequate fluids are essential after the examination to prevent barium impaction.
Upper GI examination	Radiopaque contrast material is swallowed or inserted by NG tube.	Normal gastric emptying and no other abnormalities	Study outlines the stomach and pyloric canal and can be used to determine gastric emptying time.	Preparation includes teaching and keeping the child on NPO status for 4 hr before the examination. Adequate fluids are essential after the examination to prevent barium impaction.
Barium enema, air-contrast barium enema examination	Radiopaque contrast material or air (or both) is placed in the large intestine via the rectum.	Patent bowel and no abnormalities	Study used to identify abnormalities on the surface of the bowel lumen and to determine bowel patency. It also provides hydrostatic reduction of intussusception.	Preparation includes teaching, keeping the child on NPO status, and bowel cleansing. Adequate fluids are essential after the examination to prevent barium impaction.
CT scan	Oral radiopaque contrast material often used. May also use IV or rectal contrast.	Normal anatomy without evidence of inflammation	Used to identify inflammatory conditions and appendicitis.	No patient preparation other than teaching. Sedation may be used if child unable to remain still. Can be completed in less than 15 min.
Other
Ultrasound	Study uses sound waves noninvasively to image anatomy and inflammation.	No abnormalities	Performed to identify anatomic abnormalities and inflammatory conditions.	Preparation includes teaching. For pelvic ultrasound, a full bladder is needed to improve imaging of pelvic organs.
Breath hydrogen test	Carbohydrate solution is given by mouth and exhaled. Breath samples are collected over 3 hr.	Less than 20 ppm above baseline	Used to diagnose maldigestion or malabsorption syndromes. Inadequately digested carbohydrate produces hydrogen when acted on by GI flora.	Nursing preparation entails teaching about the procedure. The child prepares by fasting for 4½ hr. The study is noninvasive. A facemask may be worn to collect expired air.

ALT, Alanine transaminase; AST, Aspartate transaminase; CT, Computed tomography; GI, gastrointestinal; IV, intravenous; NG, nasogastric; NPO, nothing by mouth.

MAJOR DIGESTIVE ENZYMES

LOCATION	ENZYME	FUNCTION
Mouth	Amylase	Converts complex carbohydrate to simple carbohydrate.
Stomach	Pepsin	Converts proteins to proteases.
Small intestine	Enterokinase	Activates trypsin.
	Peptidases	Convert peptides to amino acids.
	Sucrase, maltase, lactase	Convert disaccharides to monosaccharides.
Pancreas	Trypsin	Converts peptides to amino acids.
	Lipase	Converts fat to fatty acids and glycerol.
	Amylase	Converts carbohydrates to disaccharides.
Liver, gallbladder	Bile	Emulsifies fat, allowing the lipase to function.
Liver, gallbladder	Bile	Increases fat and fat-soluble vitamin absorption.

rise to the following three sections of the GI tract, each having an individual blood supply and rate of development:

• Foregut: From the pharynx to the duodenum, including the liver, pancreas, and biliary tract

• Midgut: From the duodenum to the transverse colon

• Hindgut: Descending colon, rectum, and anal canal

Problems in the development of each of these three sections give rise to specific malformations and disease states. Anatomically, development is complete at birth, but physiologically, the neonate’s GI tract is immature.

Fetal swallowing, intestinal motility, and defecation are detectable in the second trimester of gestation, but the most rapid and extensive development of the GI system occurs in the third trimester. The newborn must be able to adapt from total parenteral nutrition to total enteral nutrition because the placenta no longer performs nutrient exchange and waste removal.

PEDIATRIC DIFFERENCES IN THE GASTROINTESTINAL SYSTEM

• Infants have minimal saliva.

• Swallowing is not under voluntary control until 6 weeks.

• Infants and children have less stomach capacity:

AGE	STOMACH CAPACITY (mL)
Newborn	10-20
1 wk	30-90
2-3 wk	75-100
1 mo	90-150
3 mo	150-200
1 yr	210-360
2 yr	500
10 yr	750-900
16 yr	1500
Adult	2000-3000

• The stomach lies transversely and is horizontal in the infant’s abdomen; the abdomen is round in infants and toddlers.

• Peristaltic waves may reverse in infancy, causing regurgitation and vomiting. Peristalsis is faster; food remains in the stomach for a shorter period.

• Hydrochloric acid concentration is low until school age.

• Fever increases the rate of propulsion.

• The immature neonatal liver is not yet efficient in its detoxifying ability, which results in less vitamin and mineral breakdown than in older children.

• The large intestine is relatively short, with less epithelial lining to absorb water from a fecal mass. As a result, stools have a soft consistency and peristalsis is more rapid.

Children with GI alterations and their families have many special needs. Some GI problems begin at birth, with life-threatening consequences. Some require the parents to accept their child’s altered appearance. Other problems develop after birth and provide long-term challenges in management and treatment. Sudden, unexpected surgery may be necessary. GI alterations cause anxiety and affect nutrition, elimination, respiratory status, skin integrity, body image, family processes, growth and development, and educational needs.

Upper and lower GI conditions can be categorized as follows:

• Developmental problems, such as cleft lip and palate, hernias, esophageal atresia, tracheoesophageal fistula, imperforate anus, and abdominal wall defects

• Problems affecting motility, such as gastroesophageal reflux, constipation, encopresis, and irritable bowel syndrome

• Inflammatory or infectious conditions, including ulcers, gastroenteritis, appendicitis, inflammatory bowel disease, and necrotizing enterocolitis

• Obstructive disorders, such as pyloric stenosis, intussusception, and Hirschsprung disease

• Malabsorption conditions, such as lactose intolerance and celiac disease

• Hepatic disorders, such as hepatitis, biliary atresia, and cirrhosis

Disorders that involve the liver and biliary tract may be the result of congenital malformations or acquired infection. Because the liver is important to metabolism, alterations in its function can affect many body systems, including the cardiovascular, integumentary, renal, neurologic, hematologic, and immunologic systems. These disorders can also have significant effects on growth and development. Nursing care may involve nutritional support, infection control, developmental stimulation, family support, and intensive physiologic care during a period of crisis.

Disorders of Prenatal Development

Cleft Lip and Palate

Cleft lip, cleft palate, and cleft lip and palate are separate anomalies that are closely related in etiology, pathophysiology, and nursing care. These distinct problems are all abnormal openings in the lip or palate. The defects may occur unilaterally (on either side) or bilaterally and are the most common congenital craniofacial deformity.

Incidence

The incidence ranges from 1 in 700 to 1000 births for cleft lip and palate and 1 in 2000 for cleft palate alone (Cleft Palate Foundation, 2007; March of Dimes, 2007; Zarate, Martin, Hopkin, et al., 2010). Cleft lip is seen predominantly in male infants and cleft palate in female infants. The prevalence of cleft lip and/or palate is higher in Asians and Native Americans and has a lower frequency in African-Americans. The etiology of cleft lip and palate malformations is thought to be multifactorial, including both genetic and environmental factors (Rojas-Martinez, Reutter, Chacon-Camacho, et al., 2010). While there appears

PATHOPHYSIOLOGY

Cleft Lip and Palate

Cleft lip and cleft palate occur from embryonic developmental failures related to multiple genetic and environmental factors. These developmental failures result in an abnormal opening in the lip, palate, and, sometimes, nasal cavity. Cleft lip results when the medial nasal and maxillary processes fail to join at 6 to 8 weeks of gestation. Cleft palate results from failure of the primary palatal shelves, or processes, to fuse at 7 to 12 weeks of gestation.

Each of these abnormalities appears as a distinct malformation, but they may also appear together. Achieving suction during feedings may be impossible, and fluids may enter the nose, putting the child at risk for aspiration, feeding difficulties, and respiratory distress.

Child born with a cleft lip and palate, before **(A)** and after **(B)** repair. Repair of facial clefts usually requires multiple surgeries at different stages in the child’s growth. Early repair of a cleft lip facilitates parent-infant bonding and improves feeding. Children generally experience good outcomes with today’s surgical, orthodontic, and speech therapy techniques. (Courtesy Children’s Medical Center, Dallas, TX.)

to be a genetic pattern or familial risk involved, environmental factors, such as maternal smoking, have been found to be associated with an increased risk of oral cleft defects (Lebby, Tan, & Brown, 2010). Many infants who are affected with cleft lip and palate have other associated defects.

Manifestations and Diagnostic Evaluation

Cleft lip has the following manifestations: a notched vermilion border, variably sized clefts that involve the alveolar ridge, and dental anomalies (usually deformed, supernumerary, or absent teeth). Cleft palate includes nasal distortion, midline or bilateral cleft with variable extension from the uvula and soft and hard palates, and exposed nasal cavities.

The diagnosis of cleft lip and cleft palate is based on observation at birth and complete examination in the neonatal period. Diagnosis may also be made in utero with ultrasound. Cleft lip is readily diagnosed through inspection of the lip. The first sign of cleft palate may be formula coming from the nose. A gloved finger placed in the mouth to feel the defect of the palate or visual examination with a flashlight confirms the diagnosis.

Therapeutic Management

Management is based on the severity of the defect. A number of professionals are involved in this process, including surgeons; nurses; geneticists; psychologists or psychiatrists; ear, nose, and throat specialists; audiologists; and occupational and speech therapists. Orthodontists and plastic surgeons become involved in the lengthy management. Pediatricians provide ongoing child health care.

The first intervention involves modifying feeding techniques as needed to allow adequate growth. Use of special feeding techniques, obturators, and unique nipples and feeders can usually accomplish this goal and allow early discharge home with parents (Figure 43-1). These modified techniques can decrease the energy required for the infant to take in adequate nutrition. Before surgical repair, removable orthopedic devices such as a Latham device may be used to expand and realign parts of the palate or decrease the size of a wide lip cleft.

FIG 43-1 Before and after repair of a cleft lip or palate, special feeding techniques are essential for adequate nutrition. A feeder with compressible plastic sides allows gentle squeezing of the sides of the bottle to help eject the breast milk or formula. A slightly longer nipple allows the milk to be swallowed with less chance of milk entering the nasopharynx and without stimulating the gag reflex.

Cleft lip repair is usually performed by age 3 to 6 months. Early repair may improve bonding and makes feeding much easier. The surgical technique involves the use of a staggered suture line to minimize scarring. Some cosmetic modifications may be needed again at age 4 to 5 years.

Cleft palate repair is individualized and based on the degree of deformity and size of the child. Closure is completed between ages 6 and 24 months. Most teams recommend repair by 1 year of age. Earlier closure facilitates speech development.

Concurrent treatment of altered dentition, recurring otitis media, speech dysfunction, emotional issues, and cosmetic concerns completes the ongoing therapy. Children with cleft palate are at high risk for developing chronic otitis media, which can cause long-term hearing loss.

Esophageal Atresia with Tracheoesophageal Fistula

Esophageal atresia (EA) and tracheoesophageal fistula (TEF) are congenital malformations in which the esophagus terminates before it reaches the stomach and/or a fistula is present that forms an unnatural connection between the esophagus and the trachea. Figure 43-2 portrays the most common type of EA with a distal TEF.

FIG 43-2 Most common type of esophageal atresia (EA) and tracheoesophageal fistula (TEF).

Etiology and Incidence

The cause of TEF and EA is unknown. EA with or without TEF occurs in 1.2 to 4.67 in 10,000 live births, with no difference by gender (National Birth Defects Prevention Network, 2009). Nearly half of infants born with EA have other associated anomalies of the cardiac, GI, and central nervous systems. Prematurity and low birth weight are frequent concomitant problems that significantly impact long-term prognosis.

Manifestations

• Failure to pass suction catheter, nasogastric (NG) tube at birth

• Excessive oral secretions, coughing, choking

• Vomiting

• Abdominal distention

• Airless, scaphoid abdomen (atresia without fistula)

Diagnostic Evaluation

A history of maternal polyhydramnios is a significant prenatal clue. If TEF is suspected prenatally, diagnosis can be made at the ideal time—in the delivery room. Atresia should be suspected if an NG tube cannot be passed 10 to 11 cm beyond the gum line. This suspicion is confirmed with an abdominal radiograph that

PATIENT-CENTERED TEACHING

Home Care of the Child with Cleft Lip or Palate

Your infant may require a special feeding method to maximize growth while waiting for surgery, and you may need to practice the feeding method to be used after surgery until the incision heals. The feeding method you use will be based on what works for your child and what your physician recommends. In general, the following apply:

• Breastfeeding may be possible if your child has a small cleft lip or palate.

• A soft plastic, compressible bottle will prevent your child from having to suck vigorously because the breast milk or formula can be squeezed into the mouth, if needed.

• A longer nipple may allow the milk to be swallowed without entering the nose. It must not be so long that it causes gagging. Enlarging the nipple hole or “cross-cutting” a nipple may also be effective.

• A syringe with a rubber tip may also be used, especially after surgery.

• Feed your child slowly and provide short periods of rest for swallowing; children usually develop a feeding pattern of sucking, swallowing, and resting that helps them become more efficient eaters.

• Try to keep your child in an upright position during feedings to allow gravity to assist in the feeding and decrease the chance that your child might choke.

• Burp your child frequently because excess air is often swallowed.

Before surgical repair, devices may be placed in your child’s mouth to help line up the cleft in the palate for better surgical repair or to decrease the size of the lip cleft. These devices may require special care and cleaning. Consult your cleft team and nurses for specific instructions about your child’s device.

After surgery, elbow restraints (“no-no’s”) may be used so that your baby cannot touch the stitches. The following are recommendations:

• Do not apply the restraints too tightly. They should be loose but still prevent elbow bending.

• Remove “no-no’s” every 2 hours for 10 to 15 minutes and play games with your child that encourage movement of the elbows. Look for any skin irritation every time you remove an elbow restraint.

• Remove only one elbow restraint at a time.

Position your child for sleep on the back, so the child does not rub the stitches on the linens. An infant seat may be used.

Do not brush your child’s teeth for 1 to 2 weeks after surgery. Feeding a small amount of water after meals will help keep the teeth clean. Clean your child’s lip as recommended by your physician. If ordered, you may use a cotton swab and a gentle rolling motion down the suture line and then apply antibiotic ointment using the same technique.

Make use of the many support professionals in following your child for speech, hearing, dental, or orthodontic problems.

Contact the American Cleft Palate-Craniofacial Association and the Cleft Palate Foundation at www.cleftline.org for further information.

will identify a proximal esophagus dilated with air (atresia) or abdominal distention (fistula). The radiologist can identify the specific type of defect after instilling less than 1 mL of a water-soluble contrast medium into the NG tube and documenting its movement into the tracheal tree and the proximal pouch. This is then withdrawn from the pouch to minimize the risk of aspiration. Bronchoscopy and endoscopy are also used to identify and assess fistulas. The infant needs to have diagnostic testing for commonly associated cardiac and other congenital anomalies because these often are seen with this type of anomaly (Kahn & Orenstein, 2011a).