What are abdominal disorders?

Causes and Symptoms

The main trunk, or torso, of the human body includes three major structures: the chest cavity, contained within the ribs and housing the lungs and heart; the abdomen, containing the stomach, kidneys, liver, spleen, pancreas, and intestines; and the pelvic cavity, housing the sexual organs, the organs of elimination, and related structures.

The abdomen is, for the most part, contained within a membrane called the peritoneum. The stomach lies immediately below the chest cavity and connects directly with the small intestine, a long tube. It fills the bulk of the abdominal cavity, winding around and down to the pelvic bones in the hips. The small intestine then connects to the large intestine, which extends upward and crosses the abdomen just below the stomach and then turns down to connect with the rectum. Other vital organs within the abdominal cavity include the liver, kidneys, spleen, pancreas, and adrenal glands. All these structures are subject to infection by viruses, bacteria, and other infective agents; to cancer; and to a wide range of conditions specific to individual organs and systems.

Diseases in the abdominal cavity are usually signaled by pain. Identifying the exact cause of abdominal pain is one of the most difficult and important tasks that the physician faces. The familiar stomachache may be simple indigestion, or it may be caused by spoiled, toxic foods or by infection, inflammation, cancer, obstruction, or tissue erosion, among other causes. It may arise in the stomach, the intestines, or other organs contained within the abdominal cavity. In addition, pain felt in the abdomen may be referred from other sources outside the abdominal cavity. A good example would be a heart attack, which arises in the chest cavity but is often felt by the patient as indigestion. Another example is the abdominal cramping that is often associated with menstruation and premenstrual syndrome (PMS). However, because severe abdominal pain could mean that the patient is in great danger, the physician must decide quickly what is causing the pain and what to do about it.

By far the most common cause of
stomach pain is indigestion, but this term is so broad as to be almost meaningless. Indigestion can be brought on by eating too much food or by eating the wrong foods or tainted foods; it can be brought on by alcohol consumption, smoking, poisons, infection, certain medications such as aspirin, and a host of other causes. It may be merely an annoyance, or it may indicate a more serious condition, such as gastritis, gastroenteritis, an ulcer, or cancer.

The stomach contains powerful chemicals to help digest foods. These include hydrochloric acid and chemicals called pepsins (digestive enzymes). To protect itself from being digested, the stomach mounts a defense system that allows the chemical modification of foods while keeping acid and pepsin away from the stomach walls. In certain people, however, the defense mechanisms break down and bring the corrosive stomach chemicals into direct contact with the stomach walls. The result can be irritation of the stomach lining, called gastritis. Gastritis may progress to a peptic ulcer, identified as a gastric ulcer if the inflammation occurs in the stomach wall or a duodenal ulcer if it occurs in the wall of the duodenum, the first section of the small intestine. In most cases, the ulcer is limited to the surface of the tissue. In severe cases, the ulcer can perforate the entire wall and can be life-threatening.

A common cause of stomach pain is the medication used to treat arthritis and rheumatism. These drugs include aspirin and a group of related drugs called nonsteroidal anti-inflammatory drugs (NSAIDs). As part of their activity in reducing bone and joint inflammation and pain, NSAIDs interfere with part of the stomach’s network of self-protective devices and allow acids to attack stomach and duodenal walls, sometimes resulting in gastritis or ulceration.

Bacterial and
viral infections often result in abdominal distress. Foods that sit too long unrefrigerated provide a good environment for bacteria to grow. These bacteria may be inherent in the food itself (for example, Salmonella in poultry and E. coli in meats) or they may come from the hands of people who prepare and serve them. The bacteria may cause human infection directly, or they may release toxins into the food. The result can be mere annoyance, debilitating illness, or deadly infection, depending upon the organism involved. Salmonella and Staphylococcus are two of the many bacteria that can cause food poisoning. Toxin-producing E. coli can be acquired from improperly cooked meat and can cause fatal infections. Clostridium botulinum toxin, occasionally found in canned or preserved foods, leads to probably the most serious form of food poisoning; victims often do not recover.

Other bacterial and viral infections of the gastrointestinal tract are also common causes of abdominal disease. Some of these viruses and bacteria include noroviruses, rotavirus, and Shigella. Viral gastroenteritis is the second most common disease in the United States (after upper respiratory tract infections) and a leading cause of death in infants and the elderly.

Appendicitis (inflammation of the appendix) is frequently seen. The appendix is a tiny organ at the end of the small intestine. It has no known purpose in the physiology of modern humans, but occasionally it becomes infected. If the infection is not treated quickly, the appendix can burst and spread infection throughout the abdominal area, a condition that can be life-threatening.

Diarrhea, with or without accompanying abdominal pain, is a major symptom of gastrointestinal disease. It is commonly associated with bacterial or viral infection but may also be attributable to the antibiotics used to treat bacterial infections, or to noninfectious inflammatory conditions such as Crohn’s disease or ulcerative colitis.

Other gastrointestinal diseases are peritonitis (inflammation of the membrane that covers the abdominal organs), diverticulitis, constipation, obstruction, colitis, and the various cancers that can afflict the gastrointestinal system, such as stomach and colon cancers. The latter is one of the more common, yet preventable, forms of cancer in the United States.

The liver is the largest internal organ in the human body and perhaps the most complicated; it is subject to a wide range of disorders. It is the body’s main chemical workshop, and it is responsible for a large number of activities that are vital to body function. The liver absorbs nutrients from the intestinal tract and metabolizes them; that is, the liver modifies nutrients so that they can be used by the cells. The liver introduces nutrients into the bloodstream, supplying it with glucose, protein, and other substances that the body needs. The liver detoxifies the blood and allows poisons, drugs, and other harmful agents to be eliminated. The liver also manufactures and stores many important substances, such as vitamin A and cholesterol.

Chief among
liver disorders are the various forms of hepatitis and cirrhosis. Hepatitis is inflammation of the liver, and it can be caused by a viral infection, alcohol, or drugs. There are many forms of viral hepatitis; the three most significant are hepatitis A, B, and C.

Hepatitis A is the most common form; it is caused by a virus that is transmitted through contaminated food or water. Hepatitis B and C are blood-borne diseases; that is, these viruses are carried in the blood and in other body fluids, such as semen and saliva. They can be transmitted only when infected body fluids are transferred from one person to another. These diseases are commonly spread through the use of contaminated needles and during surgical and dental procedures. Nurses and other staff members in health care facilities can be exposed to hepatitis B and C when taking and handling infected blood samples. A pregnant woman who is infected can pass the disease on to her fetus. In the past, blood transfusions were a common source of infection; however, blood tests for these viruses are now available. Potential blood donors are screened, and those who test positive cannot donate blood.

Cirrhosis develops when the liver is damaged by some substance such as alcohol. Liver cells are destroyed, and as the liver attempts to regenerate, scar tissue is formed. The steady flow of blood through the organ is impeded, as are vital functions such as the removal of waste materials from the blood.

The liver is also subject to a number of cancers. Cancer cells can spread to liver tissue from other parts of the body, or they can originate there as a result of hepatitis B or C or other chronic liver diseases such as cirrhosis.

The gallbladder is a small sac connected to the liver. The liver manufactures bile, a substance that aids in the digestion of fats. Bile is stored in the gallbladder and passes through the bile duct into the small intestine. A common disorder of the gallbladder is the formation of gallstones, crystalline growths that can be as fine as sand or as large as a golf ball. If the stones clog the passage to the bile duct, severe pain may result. Removal of the gallbladder (cholecystectomy) is often necessary.

The pancreas, a vital gland situated near the liver, contains both exocrine tissue (which produces digestive enzymes) and endocrine tissue (which produces the hormone insulin). Both are subject to disease. Dysfunction of the endocrine portion (“Islets of Langerhans”) causes
diabetes mellitus, a disorder of glucose metabolism.
Pancreatitis is a potentially life-threatening inflammation of the pancreas caused most frequently by gallstones or by alcohol and other toxins.

The other major organ system in the abdomen is comprised of the kidneys and the urinary tract. The system includes the two kidneys, which sit in the middle of the back on either side of the spine; the two ureters, which transport urine from the kidneys; the bladder, a pouchlike organ that collects the urine; and the urethra, which expels urine from the body. The kidneys and related organs are subject to several disorders. Infection of the bladder or kidneys is quite common, particularly in young women and in the elderly. Kidney stones are also common and may be familial. Illnesses in other organs and systems may be reflected in the kidneys, and cancer may be primary in the kidney or may spread there from another site. Medications, other drugs, and toxins may cause severe kidney damage as well.

The peritoneum is the membranous lining of the abdominal cavity. When the organs within the cavity become inflamed, and particularly if there is any leakage of their contents, the peritoneum also becomes inflamed, a condition called peritonitis.

Treatment and Therapy

Many abdominal disorders are related to the overproduction of stomach acids, which damage the intestinal walls; the treatment of such conditions is often associated with changes in lifestyle. In treating gastrointestinal reflux disease, or GIRD, in which stomach acid backs up into the throat, physicians may suggest that the patient change habits that may be contributing to the condition, perhaps by stopping smoking, reducing the intake of alcohol, losing weight, and avoiding certain foods and medications. Preparations to neutralize stomach acids are used, as well as drugs that reduce the amount of stomach acid produced. Surgery is rarely indicated.

Hiatal hernia, the protrusion of part of the stomach through the diaphragm, usually produces no symptoms. There may be reflux of stomach acids into the esophagus, which can be treated by the same methods used in treating gastrointestinal reflux disease. Surgery is sometimes indicated.

Gastritis is commonly treated with agents that neutralize stomach acid or other agents that reduce the production of stomach acid. When gastritis appears to be caused by drugs taken for arthritis or rheumatism (for example, aspirin or NSAIDs), the physician may change the drug or the dosage to reduce stomach irritation.

In treating gastric and duodenal
ulcers, the physician seeks to heal the ulcers and prevent their recurrence. Acid-neutralizing agents are sometimes helpful, but more often agents such as histamine (H2) blockers and proton pump inhibitors that reduce the flow of stomach acids are used. It has been suggested that gastritis and ulcers are associated with certain bacteria. Consequently, some physicians add antibiotics to the regimen to destroy the pathogens. Surgery is sometimes required to control bleeding from ulcers.

Bacterial infections in the gastrointestinal tract are, as a rule, self-limiting. They run their course, and the patient recovers. Sometimes, however, appropriate antibiotics are needed. Likewise, little other than supportive therapy can be offered for most viral infections.

Appendicitis is usually treated surgically. Peritonitis, whether resulting from appendicitis or from other causes, is treated with antibiotics following surgical repair of the primary problem.

Most cases of hepatitis A resolve without complication; no specific treatment is available. Bed rest, dietary measures, and general support procedures are the only steps that can be taken. Hepatitis B and C can become chronic and can progress to chronic active hepatitis, which may lead to liver failure, cirrhosis, liver cancer, and death. New treatments with antiviral drugs and immune modulators such as interferon are curative in some patients. Vaccines against both hepatitis A and B are available and recommended for all children and for adults who are at high risk. There is no vaccine for hepatitis C. There is no treatment for cirrhosis, although physicians may be able to treat some of its complications.

Kidney infections are usually readily treated with antibiotics. Kidney stones often require surgical removal or lithotripsy, a procedure in which ultrasonic waves are used to break up the stones. Recurrence is common, but sometimes can be prevented with dietary changes or medication.

"Abdominal Pain." MedlinePlus, Apr. 20, 2013.

American College of Gastroenterology.

Barrett, Amanda, and Daus Mahnke. "Acute Abdomen." Health Library, Oct. 31, 2012.

Guillory, Gerard. IBS: A Doctor’s Plan for Chronic Digestive Disorders. 3d ed. Point Roberts, Wash.: Hartley & Marks, 2001.

"Hepatitis." Centers for Disease Control and Prevention, Mar. 12, 2013.

Kapadia, Cyrus R., James M. Crawford, and Caroline Taylor. An Atlas of Gastroenterology: A Guide to Diagnosis and Differential Diagnosis. Boca Raton, Fla.: Parthenon, 2003.

Litin, Scott C., ed. Mayo Clinic Family Health Book. 4th ed. New York: HarperResource, 2009.

Runge, Marschall S., and M. Andrew Gregnati, eds. Netter’s Internal Medicine. 2d ed. Philadelphia: Saunders/Elsevier, 2009.