11.3 General Assessment of the Gastrointestinal System

When evaluating a client with a potential gastrointestinal disorder, the nurse must pay special attention to their particular risk factors, as well as the influence of their cultural beliefs and socioeconomic factors. All these factors may affect their overall gastrointestinal health, as well as their response to treatment.

Risk Factors

There are several risk factors that, when present, can contribute to the development of gastrointestinal (GI) disorders, including the following^{[1],[2],[3],[4],[5]}:

• Diet can play a large role in the development of gastrointestinal disorders. For instance, a low-fiber diet puts the client at risk for constipation, as well as diverticulosis. The use of alcohol can contribute to gastroesophageal reflux disease and can lead to impaired nutrition absorption and increased incidence of diarrhea, as well as the risk of esophageal cancer. Diets high in fat have also been linked to inflammatory bowel disease, as well as the immune health of the gastrointestinal system.
• Inactivity puts the client at risk for constipation due to reduced GI motility. Inactivity also promotes obesity, which is a risk factor for a variety of gastrointestinal disorders.
• The use of certain medications such as iron supplements and opioids can contribute to constipation.
• A family history of GI disorders can put the client at elevated risk. For instance, colon cancer and inflammatory bowel disease tend to run in families.
• Age is also a significant risk factor. The elderly undergo a number of physiologic changes that predispose them to gastrointestinal issues. For instance, elderly clients tend to experience alterations in taste, which may put them at risk for malnutrition. Elderly clients have a reduction in LES pressure, predisposing them to gastroesophageal disease. Additionally, they also have a reduction in blood flow to the stomach and decreased protective systems, putting them at greater risk for peptic ulcer disease.
• Stress resulting from acute illnesses and burns can contribute to the development of peptic ulcer disease.

Cultural Factors

A variety of cultural factors can also influence health and illness as it relates to the gastrointestinal tract. A client’s ethnic heritage can affect how a gastrointestinal disorder presents. For instance, African Americans with inflammatory bowel disease tend to have more complex GI disorders and suffer from more complications when compared to other ethnicities. Food also plays a significant role in cultural traditions and can, therefore, affect the gastrointestinal system. For example, clients who are vegan avoid the ingestion of animal products. Therefore, nurses must take cultural beliefs into account when counseling the client on dietary intake as it relates to a particular disorder.^[6]

Client terminology and language can also be important when assessing the client’s gastrointestinal system. Bloating is a common symptom of many GI disorders; however, this term does not translate well in many languages. Therefore, clients whose primary language is other than English may use the word “distention” instead. Clients may also treat their gastrointestinal ailments with complementary or alternative medications, so nurses must assess for the use of these treatments, in addition to mainstream medications.^[7]

Cultural beliefs regarding family structure can also impact gastrointestinal health. Some clients have a wide network of extended family members they can rely on as a support system, whereas other clients have a smaller nuclear family with less social support available. Studies have shown that clients who have more family support tend to rate their symptoms as less distressing than those who do not have the same level of family support.^[8]

A client’s culture can have a significant impact on their health care outcomes. As health care professionals, we must demonstrate cultural humility and ask about and respect client’s cultural values, perspectives, and beliefs.

Socioeconomic Factors

Socioeconomic factors refer to things like education levels, employment, access to health care, and access to healthy food. All these factors can directly impact the health of individuals and must be taken into account when assessing the gastrointestinal system. For example, individuals with less education may have difficulty obtaining a well-paying job with health insurance. They may be unable to afford medications required to manage chronic gastrointestinal conditions. Limited access to health care can also prevent them from obtaining a recommended health care screening like a colonoscopy, causing a delay in diagnosis and treatment of gastrointestinal disorders.^[9]

Food insecurity, a lack of food due to financial or other resources, is a risk factor for developing many chronic diseases. Additionally, food insecurity can make it difficult to follow recommended dietary plans due to a lack of access to various food options. Nurses assess the impact of potential socioeconomic factors as a holistic approach to health care and address these factors in the nursing care plan to help the client achieve optimal health care outcomes.^[10]

Assessment

Health History

A focused gastrointestinal subjective assessment collects data about the signs and symptoms of GI diseases, including any digestive or nutritional issues, relevant medical or family history of GI diseases, and any current treatment for related issues. Table 11.3 outlines interview questions used to explore medical and surgical history, symptoms related to the gastrointestinal system, and associated medications. Information gained from the interview process is used to tailor the subsequent physical assessment and create a plan for client care and education.^[11]

Table 11.3. Interview Questions for Subjective Assessment of GI System^[12]

Pain is the most common complaint related to abdominal problems and can be attributed to multiple underlying etiologies. Because of the potential variability of contributing factors, a thorough assessment of this common chief complaint should occur. Additional questions include asking if the client has bloody stools (hematochezia); dark, tarry stools (melena); bloating (abdominal distention); or vomiting of blood (hematemesis).^[13]

Nausea, vomiting, diarrhea, and constipation are common issues experienced by hospitalized clients due to side effects of medications or medical procedures. It is important for nurses to ask a hospitalized client daily about the date of their last bowel movement so that a bowel management program can be initiated if necessary. If a client is experiencing diarrhea, nurses should assess for signs of dehydration or electrolyte imbalances. Dehydration can be indicated by dry skin, dry mucous membranes, or sunken eyes. These symptoms may require prompt notification of the health care provider for further treatment.^[14]

Additional specialized assessments of GI system function can include examination of the oropharynx and esophagus. For example, clients who have experienced a cerebrovascular accident (CVA), also called a stroke, may experience difficulty swallowing (dysphagia). The nurse is often the first to notice these difficulties in clients who are swallowing pills, liquid, or food and can advocate for treatment to prevent complications, such as aspiration pneumonia.^[15]

Physical Assessment

In preparation for the physical assessment, the nurse should create an environment in which the client will be comfortable. Encourage the client to empty their bladder prior to the assessment. Warm the room and stethoscope to decrease tensing during assessment.^[16]

Physical examination of the abdomen includes inspection, auscultation, palpation, and percussion. Note that the order of physical assessment differs for the abdominal system compared to other systems. Palpation should occur after the auscultation of bowel sounds so that accurate, undisturbed bowel sounds can be assessed. The abdomen is divided into several abdominopelvic quadrants, as illustrated in Figure 11.18^[17]. When assessing the abdomen, the nurse considers the organs located in the quadrant being examined.^[18]

Inspection

The abdomen is inspected by positioning the client supine on an examining table or bed. The head and knees should be supported with small pillows or folded sheets for comfort and to relax the abdominal wall musculature. The client’s arms should be at their side and not folded behind their head because this position tenses the abdominal wall. Visually examine the abdomen for overall shape, masses, skin abnormalities, and any abnormal movements^[19]:

• Observe the general contour and symmetry of the entire abdominal wall. The contour of the abdomen is often described as flat, rounded, scaphoid (sunken), or protuberant (convex or bulging).
• Assess for distention. Generalized distention of the abdomen can be caused by obesity, bowel distention from gas or liquid, or fluid buildup.
• Assess for masses or bulges, which may indicate structural deformities like hernias or be related to disorders in abdominal organs.
• Assess the skin for uniformity of color, integrity, scarring, or striae. Striae are white or silvery elongated marks that occur when the skin stretches, especially during pregnancy or excessive weight gain.
• Note the shape of the umbilicus; it should be inverted and midline.
• Carefully note any scars and correlate these scars with the client’s recollection of previous surgeries or injury.
• Document any abnormal movement or pulsations. Visible intestinal peristalsis can be caused by intestinal obstruction. Pulsations of the aorta may be seen in the epigastric area in clients who are especially thin, but otherwise should not be observed. The presence of a strong pulsating mass could indicate an aortic abdominal aneurysm.^[20]

Auscultation

Auscultation follows inspection for accurate assessment of bowel sounds. Use a warmed stethoscope to assess the frequency and characteristics of the client’s bowel sounds, which are also referred to as peristaltic murmurs.^[21]

Begin the assessment by gently placing the diaphragm of the stethoscope on the right lower quadrant (RLQ) because bowel sounds are consistently heard in that area. Bowel sounds are generally high-pitched, gurgling sounds that are heard irregularly. The stethoscope is moved to the next quadrant in a clockwise motion around the abdominal wall.^[22]

It is not recommended to count abdominal sounds because the activity of normal bowel sounds may cycle with peak-to-peak periods as long as 50 to 60 minutes. The majority of peristaltic murmurs are produced by the stomach, with the remainder from the large intestine and a small contribution from the small intestine. Because the conduction of peristaltic murmur is heard throughout all parts of the abdomen, the source of peristaltic murmur is not always at the site where it is heard.^[23]

Hyperactive bowel sounds may indicate bowel obstruction or gastroenteritis. Sometimes a client’s bowel sounds can be heard without a stethoscope (borborygmus), often described as “stomach growling.” This is a common example of hyperactive sounds. Hypoactive bowel sounds may be present with constipation, after abdominal surgery, peritonitis, or paralytic ileus. As the abdomen is auscultated, vascular sounds should not be heard, such as a bruit. Vascular sounds should be reported to the health care provider.^[24]

Palpation

Palpation of the abdomen involves using the flat of the hand and fingers (not the fingertips) to detect palpable organs, abnormal masses, or tenderness. If a client is reporting abdominal pain, that area should be palpated last. Light palpation is primarily used by bedside nurses to assess for musculature, abnormal masses, and tenderness. During light palpation, the skin of the abdomen is pressed about one centimeter beginning in the right lower quadrant, and then palpation is moved around the abdomen in a clockwise manner. Deep palpation is a technique used by advanced practice clinicians to assess for enlarged organs.

When palpating the abdomen, note the client’s response, such as guarding, rigidity, or rebound tenderness. Voluntary guarding refers to voluntary contraction of the abdominal wall musculature, usually the result of fear, anxiety, or the touch of cold hands. Involuntary guarding is the reflexive contraction of overlying abdominal muscles as the result of peritoneal inflammation. Rigidity refers to involuntary contraction of the abdominal musculature in response to peritoneal inflammation, a reflex the client cannot control. Rebound tenderness is a sign of peritoneal inflammation. To elicit rebound tenderness, the clinician maintains pressure over an area of tenderness and then withdraws the hand abruptly. If the client winces with pain upon withdrawal of the hand, the test is positive.^[25]

Percussion

Percussion is typically performed by advanced practice registered nurses or other health care providers to assess the size of the liver and spleen or to determine if costovertebral angle (CVA) tenderness is present, a sign of inflammation of the kidney. Percussion can also indicate the presence of fluid or gas because the sound made during percussion changes based on density. For instance, tympanic sounds indicate the presence of gas or fluid, and dull sounds are heard over dense organs. The change in expected sounds heard during percussion can indicate abnormalities. For instance, the intestines normally elicit tympanic sounds. However, if dullness is heard while percussing the skin over the intestines, it can indicate that increased stool or a mass is present.^[26]

Common Laboratory and/or Diagnostic Tests

Laboratory and/or diagnostic testing is often ordered by health care providers to help aid in the diagnosis of gastrointestinal alterations. Although each GI disorder described later in this chapter will specify typical labs and/or diagnostic tests used to diagnose that specific condition, this section will provide a general overview of common gastrointestinal diagnostic tests, including the categories of lab tests, imaging, and endoscopy.

Lab Tests

Common lab tests used to assess the gastrointestinal system are a complete blood count, a comprehensive metabolic panel, stool studies, serum lipase, and inflammatory markers^{[27],[28],[29],[30],[31],[32],[33],[34]}:

• A complete blood count (CBC) measures the levels of red blood cells, white blood cells, hemoglobin, hematocrit, and platelets in the blood. In cases of GI dysfunction, any of these values could be abnormal. For instance, if a client has peptic ulcer disease and a bleeding ulcer, they may become anemic due to blood loss, reflected by decreased red blood cells, hemoglobin, and hematocrit. Additionally, poor nutritional intake due to a chronic gastrointestinal condition can cause anemia. If a client has an infectious or inflammatory condition, such as appendicitis, white blood cells are typically elevated. Abnormal platelet levels may be seen in clients with inflammatory bowel disease.

• A comprehensive metabolic panel (CMP) can be helpful in assessing gastrointestinal conditions by analyzing bilirubin, liver enzymes, albumin, and electrolyte levels. Bilirubin levels and liver enzymes may be altered with pancreatic, gallbladder, or liver disorders. Albumin levels may be decreased in cases of malnutrition due to reduced intake or poor absorption of nutrients. Electrolyte levels, particularly potassium, may be decreased with diarrhea or vomiting.
• A variety of stool studies can be used to evaluate for the presence of blood, bacteria, or parasites in the stool. A fecal occult blood test involves placing feces on a testing card and applying a chemical that detects blood not visible to the naked eye. See Figure 11.19^[35] for an example of a stool testing card. The stool sample is compared to the control window to determine if blood is present. Stool can also be cultured to check for the presence of specific bacteria. An example of a common stool culture is testing for Clostridium difficile (C. diff). Stool can also be examined under a microscope to look for the presence of ova and/or parasites.
• Serum lipase evaluates levels of lipase, an enzyme that breaks down fats. Elevated levels can be seen with pancreatic disorders.
• Two common inflammatory markers are C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). CRP is released by the liver in response to inflammation. Although CRP is not specific, meaning the test does not show the source of the inflammation, it can be useful in assessing the extent of inflammation in the body. CRP levels are commonly elevated in inflammatory bowel disease. ESR is also a blood test that can measure levels of inflammation in the body. Like CRP, ESR does not show the source of the inflammation, but it may be helpful in monitoring inflammatory conditions, such as inflammatory bowel disease.

Imaging

Common imaging techniques used to assess the gastrointestinal system are X-rays, CT scans, MRI, MRCP, ultrasound, and barium studies^{[36],[37],[38],[39],[40],[41]}:

• Abdominal X-ray: An abdominal X-ray is an imaging exam that can be used to look for sources of abdominal pain. They can also be used to assess for blockages, masses, ingestion of foreign objects, or perforations in the intestine. They can be taken in a variety of positions (standing, lying, or side lying) and can provide basic information about abdominal organs.
  • Nursing considerations for an abdominal X-ray include ensuring that the client removes anything that may interfere with the exam. The client may be asked to remove their jewelry and put on a gown. The nurse should educate the client to stay still during the X-ray and ensure that any parts of the body that are not being imaged are covered with a lead apron to protect against incidental X-ray exposure. X-rays should not be completed on those who are pregnant as the radiation can cause birth defects.

• Abdominal CT Scan: An abdominal CT scan is an imaging exam that combines the use of X-rays with computer equipment to provide detailed images of the body part that is being scanned. CT scans may be completed with or without the use of contrast, which is given orally or intravenously. When contrast is used, the body part that is being examined can be seen better than when contrast is not used. An abdominal CT scan can be done to look for causes of abdominal pain, bowel obstructions, tumors or masses, infections, or bleeding into the abdomen. A CT scan is often done when enough detail is not seen on a traditional X-ray, or the results are inconclusive.
  • Nursing considerations for an abdominal CT scan consist of assessing the client for allergies to contrast media, as well as kidney issues, as contrast dye is known to be nephrotoxic. Those who receive contrast should be encouraged to drink adequate fluids after the exam to help rid the body of the contrast. Nurses must also educate clients who take metformin about the risks associated with combining this medication with contrast media. Clients may be told to temporarily stop this medication. Prior to the exam, clients will be asked to remove their jewelry and change into a gown. Lastly, the client may need to be NPO prior to the CT scan. During the exam, the client will be encouraged to stay still.

• Magnetic Resonance Imaging (MRI): MRI is an imaging technique that uses a combination of strong magnets and radio waves to produce in-depth views of the body. Contrast dye may or may not be used with an MRI. An MRI can provide even more detail than a CT scan and does not use radiation. An MRI of the abdomen can be performed to assess for masses, infections, or causes of abdominal pain. It can also assess the lymph nodes and blood vessels of the abdomen.
  • Nursing considerations for an MRI include ensuring the client does not have any metal on or implanted within their body prior to entering the exam room due to the use of magnets. Although this list is not inclusive, clients with pacemakers, aneurysm clips, and certain implants may not be able to have an MRI performed. The client will need to change into a hospital gown that does not have any metal on it. Prior to the MRI, for better visualization of the GI tract, the client may need to be NPO. The client should also be encouraged to stay still during the exam. If contrast dye will be used, kidney function and allergies should be assessed first. Lastly, clients with claustrophobia may need to be sedated prior to receiving an MRI as it is an enclosed space. See Figure 11.20^[42] for a photo of an MRI machine.

• Magnetic Resonance Cholangiopancreatography (MRCP): MRCP uses an MRI with contrast to examine the bile ducts. This can be helpful to assess disorders of the gallbladder, pancreas, or liver. Nursing considerations are similar to that for an MRI.
• Ultrasound: An ultrasound uses sound waves to create images of the body. During an ultrasound, ultrasound gel is placed on the area of the body to be visualized, and a transducer is then placed over it. The transducer emits sound waves that echo off organs to create an image on the computer screen. An abdominal ultrasound can be used to assess for causes of abdominal pain, masses, liver issues, and gallbladder or pancreatic disorders. An ultrasound can be a helpful assessment tool for those individuals who cannot undergo imaging procedures that use radiation, such as pregnant women. They are also helpful as a quick diagnostic tool. Please see Figure 11.21^[43] for an image of a client undergoing an abdominal ultrasound.
  • Nursing considerations for an abdominal ultrasound include ensuring that the client removes anything that may interfere with the exam. The client may be asked to remove their jewelry and put on a gown. The client may need to be NPO prior to the ultrasound.

• Barium Studies: Barium studies consist of a barium enema (also known as a lower GI series) and a barium swallow (also known as a lower GI series). The use of barium, which shows up as white on X-rays, allows for better visualization of the GI tract when compared to a regular X-ray. With a barium enema, barium is inserted into the rectum via an enema, and then a series of X-rays are taken. This test allows for visualization of strictures or obstructions in the rectum, large intestine, or the most distal part of the small intestine. With a barium swallow, barium is ingested via the mouth, and then a series of X-rays are taken. With this imaging modality, the esophagus, stomach, and the initial part of the small intestine can be assessed.^[44]
  • Nursing considerations for a barium enema consist of educating the client on any necessary dietary restrictions prior to the exam. Generally, the client will need to be on a clear liquid diet the day prior, as well as be nothing by mouth after midnight. To clear the intestine of feces to enhance imaging, the client will need to take medications to help clear the bowel prior to the exam. After the exam, the client should be encouraged to drink fluids and eat foods that are high in fiber to help eliminate the remaining barium from the body. Initial stools may appear light in color due to the presence of barium.
  • Nursing considerations for a barium swallow also consist of educating the client on any necessary dietary restrictions prior to the exam. An NPO order (nothing by mouth) is often implemented at midnight prior to the exam. Similar to a barium enema, the client will also need to consume adequate fluids and fiber to help the barium be excreted from the body after the exam.

Endoscopy

Common endoscopy procedures used to assess the gastrointestinal system are colonoscopy, EGD, ERCP, and capsule endoscopy^{[45],[46],[47],[48],[49]}:

• Colonoscopy: A colonoscopy refers to the insertion of a scope into the rectum to visualize the entire colon. It is used to visualize abnormal tissue growths, inflamed areas, gastrointestinal bleeding, and ulcers. During a colonoscopy, the provider can also take tissue samples to send for biopsies. The client will receive sedation for the procedure to ensure their comfort.
  • Nursing considerations for a colonoscopy consist of educating the client on the need for bowel preparation. To do this effectively, the client must be on a clear liquid diet for 24 or more hours prior to the exam and NPO (nothing by mouth) at midnight. The client must also complete the ordered laxative regimen per provider orders. The nurse will also ensure that the informed consent is completed prior to the procedure. During the colonoscopy, the nurse may assist with client positioning, monitoring of vital signs, and providing client support as needed. After the procedure, the nurse continues to monitor vital signs and for signs of colon perforation and any rectal bleeding.
• Esophagogastroduodenoscopy (EGD): An EGD, also referred to as an “upper GI endoscopy,” is a procedure where a small tube is placed into a client’s mouth and guided through the esophagus, stomach, and duodenum. It is completed to further assess client complaints of abdominal pain, difficulty swallowing, gastroesophageal reflux disease, blood in vomit, or gastrointestinal bleeding. An EGD is also commonly done to monitor certain conditions such as Barrett’s esophagus, which is further discussed in the “Gastrointestinal Reflux Disease” section. During an EGD, the provider can also take tissue samples to send for biopsies, dilate strictures, remove foreign bodies, or treat areas that are bleeding. The client will receive sedation for the procedure to ensure their comfort.
  • Nursing considerations for an EGD consist of educating the client on the need for dietary modification prior to the exam. The client will need to be on a clear liquid diet and then NPO prior to the exam. The timing of these modifications will differ based on provider. The nurse will also ensure that the informed consent is completed prior to the procedure. During the EGD, the nurse may assist with client positioning, monitoring of vital signs, and providing client support as needed. After the procedure, the nurse continues to monitor vital signs and for signs of complications such as bleeding or bowel perforation. Due to a numbing spray that is used in the procedure, it may take some time for the client’s gag reflex to return. The client should not eat or drink until this occurs.

• Endoscopic Retrograde Cholangiopancreatography (ERCP): An ERCP is the process of inserting a scope into the client’s mouth and then into the esophagus, stomach, and the first part of the small intestine. From there, other tools can then be inserted into the ducts of the biliary/pancreatic system, and tissue samples may be taken. Contrast dye may also be injected to allow for visualization of these ducts. An ERCP may be performed for clients who have stones in the bile duct, pancreatitis, pancreatic cancer, or strictures in the biliary system. The client will receive sedation for the procedure to ensure their comfort. See Figure 11.22^[51] for an image of an ERCP.
  • Nursing considerations for an ERCP consist of educating the client on the need for dietary modification prior to the exam. The client will need to be NPO per provider order. If the client is undergoing an ERCP due to an obstruction in the biliary system, antibiotics may be ordered. During the ERCP, the nurse may assist with client positioning, monitoring of vital signs, and providing client support as needed. After the procedure, the nurse continues to monitor vital signs and for signs of complications such as pancreatitis, cholangitis (infection of the bile ducts), or biliary duct perforation.

• Capsule Endoscopy: Capsule endoscopy is used to assess the small intestine as traditional scopes cannot assess the entire small intestine. With this procedure, the client will swallow a small pill containing a recording device. The pill will travel through the client’s small intestine, collecting images as it passes through. As the pill travels through the digestive system, it sends data to a recorder that is secured externally on the client. This data will then later be reviewed by the provider to look for bleeding, abnormal tissue growth, ulcers, or the presence of inflammatory bowel disease. The pill is then excreted in the stool, normally within 24 hours. Retention of the capsule can occur in those with strictures, obstructions, or fistulas and should not be performed on these clients. No sedation is required with this procedure. See Figure 11.23^[52] for an image of a pill with a camera that can be used in a capsule endoscopy.
  • Nursing considerations for a capsule endoscopy are similar to that of a colonoscopy, as the client will also need to modify their diet preprocedure and complete colon preparation with the use of laxatives. The nurse may also assist with fitting the recorder onto the client, as well as with ingestion of the pill camera. Lastly, the nurse should educate the client on when meal resumption can occur. Two hours after ingesting the device, the client can start a clear liquid diet. Four hours after ingestion, the client can have a meal.

Life Span Considerations

When assessing infants, children, and older adults, the following life span considerations should be kept in mind^{[53],[54],[55]}:

Infants and Children

• Eating and elimination patterns of infants require special consideration based on the stage of development. Ask parents about feeding habits. Is the baby being breastfed or formula fed? If formula fed, how does the child tolerate the formula?
• To assess for urine output in infants and toddlers, assess the frequency of wet diapers and the daily number of wet diapers. In hospitalized infants and toddlers, the diapers may be weighed for precise measurements of urine output. Urine output can be used to assess hydration status.
• Note that the expected abdominal contour of an infant is called protuberant, which means bulging. The expected abdominal contour of a child is protuberant until about the age of 4.
• Assess the umbilical cord of the neonate; it should dry and fall off on its own within two weeks of life.
• Observe respiratory movement in the abdomen of the infant.
• The exocrine functions of the pancreas are not mature until one year of age.
• Infants have quicker gastric emptying times than compared to adults.
• Children often cannot provide more information than “my stomach hurts”; they may have symptoms of decreased school attendance due to abdominal discomfort.

Older Adults

• Constipation may be more common in older adults due to decreased physical mobility and oral intake, as well as polypharmacy.
• Older adults commonly have reduced saliva, which can lead to dry mouth and alterations in their ability to taste.
• Older adults have decreased LES pressure, making them more prone to gastroesophageal reflux disease.
• Decreased blood flow to the stomach, as well as decreased mucus production, put the older adult at risk for peptic ulcer disease and gastritis.
• Overgrowth of bacteria in the small intestine (leading to diarrhea, malabsorption of nutrients, and weight loss) is more common in older adults.