9
Gastrointestinal System
At the completion of this chapter the reader should be able to do the following:
1. Describe the basic anatomy of the abdomen and gastrointestinal system
2. Perform a basic examination of the gastrointestinal system, including history, inspection, auscultation, percussion, and palpation
3. Recognize conditions of the gastrointestinal system that require referral
4. Describe appropriate initial management of common disorders of the gastrointestinal tract
5. Recognize conditions of the gastrointestinal system that may preclude the athlete from participation, and which symptoms are self-limiting
Introduction
Health care providers hear complaints about abdominal pain or discomfort every day. Nausea, diarrhea, and constipation account for some of these complaints; heartburn and gastroesophageal reflux account for others. For the physically active, the stress of hectic schedules and travel for those involved in competition and the consumption of greasy or spicy foods are certainly among the causes. Often gastrointestinal disorders are transient, and although they may affect performance or the ability to compete, they are not serious conditions. Fortunately, because of working closely with the athletes, the athletic trainer can identify more serious gastrointestinal conditions that require further medical evaluation and treatment.
This chapter reviews the anatomy and physiology of the gastrointestinal system and procedures to evaluate the abdominal area, including auscultation, palpation, and percussion. This chapter also presents common disorders of the gastrointestinal system, including the signs and symptoms, diagnostic tests, and differential diagnoses. In addition, treatment of selected conditions and implications for athletic participation are discussed.
Overview of Anatomy and Physiology
The gastrointestinal system is composed primarily of a long tube between the mouth and the anus that serves to process food and fluids (Figure 9-1). From ingestion of solids and liquids through the absorption and balancing of electrolytes and finally waste production and excretion, the alimentary tract performs several vital functions. For athletes, it is unlikely that sports will cause significant gastrointestinal problems, but rather that gastrointestinal problems are common and can affect athletic performance.
The major organs of the gastrointestinal tract start with the esophagus, which connects the mouth to the stomach via a muscular band called the gastroesophageal junction or lower esophageal sphincter. The mouth and teeth, although part of the gastrointestinal tract, are discussed in Chapter 13. Within the pouch of the stomach, hydrochloric acid and enzymes such as pepsin and gastric lipase serve to break down food for later absorption in the intestines. The stomach empties through another muscular ring, the pyloric sphincter, into the duodenum, the first portion of the small intestine.
Among the many important organs in the abdomen, the gastrointestinal tract includes the liver, gallbladder, pancreas, and spleen (Figure 9-2, A) as well as the kidneys and related structures (Figure 9-2, B). Each of these essential organs helps digestive and absorptive functions of the gastrointestinal system.
The liver is a large organ located under the right diaphragm that has several crucial functions in metabolism, storage of vitamins and iron, filtering toxins from the blood, and producing critical blood proteins. Bile is produced in the liver and stored in the saclike gallbladder, where it is periodically released into the duodenum to help in the absorption of fats. The pancreas sits below the stomach and assists digestion by producing several enzymes that are also released into the duodenum. In addition, the pancreas produces the essential hormones of insulin and glucagon that are released into the blood stream for maintaining blood sugar (i.e., glucose) levels.
Most abdominal organs and the inner lining of the abdominal cavity are covered with a protective membrane called the peritoneum. When this becomes inflamed or irritated by blood or infection, the entire abdomen can become very tender and the muscles of the abdominal wall may become rigid. Individual sensory nerves do not innervate each organ within the peritoneum, which is why abdominal pain is not necessarily specific to the origin (location) of pathology.
The rectus abdominis muscle and the internal and external oblique muscles serve to protect the organs of the abdominal cavity (Figure 9-3). Just like muscles elsewhere in the body, they can be injured by overuse, acute strain, or contusions. For an athlete with abdominal pain, distinguishing whether the pain is from the internal organs or the overlying muscles is important. Sometimes this distinction can be difficult, or there may be problems with both.
When referring to the abdomen, clinicians will typically divide it into quadrants. The midline extends from the center of the sternum through the pubic bone, and the horizontal line extends through the umbilicus. This creates right and left upper and lower quadrants, commonly referred to as RUQ, LUQ, RLQ, and LLQ. This distinction becomes important and helpful in diagnosing many conditions1 (Boxes 9-1 and 9-2). Appendicitis, for example, will typically cause RLQ pain, whereas constipation can cause LLQ pain (Box 9-3). Other clinicians may use the nine-region classification, which uses two imaginary horizontal lines and vertical lines to divide the abdomen into regions (Figure 9-4).
Pathological Conditions
General Evaluation of Abdominal Pain
The patient with abdominal pain may not have a problem with the gastrointestinal tract at all. Many possible conditions, including diseases of the heart, lungs, kidneys, and musculoskeletal system, can present as “abdominal pain” (Box 9-4). For female patients, it is important to obtain an appropriate menstrual cycle history. Pain that is perceived as being abdominal may be from the reproductive system, such as ovarian cysts, menstrual cramps, pelvic infections, or complications of pregnancy. Box 9-5 gives several key questions to ask in the evaluation of abdominal conditions.
As with other conditions, the examiner must determine whether there was any trauma involved and the details of that injury. A past medical history or family history of gastrointestinal problems can also help in the diagnosis, as can social history factors, such as alcohol intake.2 Signs or symptoms that may indicate a severe or life-threatening condition constitute red flags with abdominal pain. Beyond the obvious issues such as unstable vital signs or altered mental status that are always red flags, these findings are serious enough that a physician should be contacted immediately, or the patient should be taken to an emergency department.
Physical examination of the abdomen involves the skills of inspection, auscultation, palpation, and percussion. Inspection consists of carefully examining the abdomen when the athlete is lying comfortably supine. Initially, the examiner notes the presence of scars that may indicate prior surgery and thus could decrease the concern about acute appendicitis or gallstones and looks for obvious bruising or contusions as well as swelling or distention. A yellowish tint can indicate jaundice from liver disease, or a faint bluish discoloration around the umbilicus may indicate intraabdominal bleeding. The examiner watches the movement of the abdomen as the patient breathes in and out for asymmetry that can indicate intraabdominal masses or hernia.
In distinguishing abdominal muscle pain from problems of the abdominal organs, it is helpful to have the patient tense the muscles by doing a partial sit-up. As the patient’s head is raised from the table, the muscles are held taut and muscle pain is aggravated, indicating a problem that is muscular in origin.
Auscultation is always performed before palpation in the examination of the abdomen. In the examination of the heart and lungs, palpation is done before auscultation; however, palpation of the abdomen may create abdominal sounds that were not there before palpation. Auscultation should reveal the normal clicks and gurgling of bowel sounds that may be heard anywhere from a few times to dozens of times every minute. Chapter 2 covers use of the stethoscope and basic auscultation techniques. The examiner needs to be alert to abnormal sounds, such as high-pitched tinkling sounds or rushing water sounds, as well as the potentially absent sounds that can indicate intraabdominal pathology (Figure 9-5). Some patients may have quieter abdomens; bowel sounds are not considered absent until the examiner has listened continuously for 5 minutes with no sound heard.
Percussion is a skill that requires considerable practice and is not covered in detail in this book. It may be used to assess the size and density of abdominal organs or to detect the presence of air or fluid in the abdominal cavity. In general, the examination follows a standard sequence for abdominal percussion (Figure 9-6) or percussion to determine size of the liver (Figure 9-7). As indicated in Chapter 2, percussion may be direct or indirect.
The examiner should practice percussing normal tympanic and dull sounds of the four quadrants exhibited by various positions of percussion. Tympany is the predominant sound throughout the abdomen and hollow organs because of the air contained in the stomach and intestines (Table 9-1). A dull sound is present over solid masses adjacent to hollow organs.
TABLE 9-1
Percussion Notes of the Abdomen
Sound | Description | Location |
Tympany | Musical note of higher pitch than resonance | Over air-filled viscera |
Hyperresonance | Pitch lies between that of tympany and resonance | Base of left lung |
Resonance | Sustained note of moderate pitch | Over lung tissue and sometimes over the abdomen |
Dullness | Short, high-pitched note with little resonance | Over solid organs adjacent to air-filled structures |
From Seidel HM, Ball JW, Dains JE, et al: Mosby’s guide to physical examination, ed 6, St. Louis, 2006, Mosby, p 538.
Examiners use indirect percussion to tell when they are directly over solid organs or hollow organs of the abdomen. A change in sound from tympanic to dull is easier to detect, so examiners usually start over an area known to be normally tympanic. Percussion is most commonly performed to tell the size of the liver and spleen. It is important to understand the surface anatomy of the liver (Figure 9-8) in order to assess the liver through indirect percussion (Figure 9-9).