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Medical Author:

Jay W. Marks, MD

Jay W. Marks, MD

Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.

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Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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In this Article

• What is dyspepsia (indigestion)?
• What are the symptoms of dyspepsia (indigestion)?
• What causes dyspepsia (indigestion)?
• What is the course of dyspepsia (indigestion)?
• What are the complications of dyspepsia (indigestion)?
• How is dyspepsia (indigestion) diagnosed?
• Exclusion of other diseases
• Specific tests of gastrointestinal function
• How is dyspepsia (indigestion) treated?
• What is a reasonable approach to the diagnosis and treatment of dyspepsia (indigestion)?
• What is in the future for dyspepsia (indigestion)?
• Dyspepsia (Indigestion) At A Glance
• Tummy Trouble (Digestive Disorders) FAQs
• Patient Comments: Dyspepsia - Causes
• Patient Comments: Indigestion - Treatments
• Patient Comments: Indigestion - Symptoms
• Find a local Gastroenterologist in your town
• Dyspepsia Index

The treatment of dyspepsia is a difficult and unsatisfying topic because so few drugs have been studied and have shown to be effective. Moreover, the drugs that have been shown to be useful have not been substantially effective. This difficult situation exists for many reasons, as follows:

• Life-threatening illnesses (for example, cancer, heart disease, and high blood pressure) are the illnesses that capture the public's interest and, more importantly, research funding. Dyspepsia is not a life-threatening illness and has received little research funding. Because of the lack of research, an understanding of the physiologic processes (mechanisms) that are responsible for dyspepsia has been slow to develop. Effective drugs cannot be developed until there is an understanding of these mechanisms.
• Research in dyspepsia is difficult. Dyspepsia is defined by subjective symptoms (such as pain) rather than objective signs (for example, the presence of an ulcer). Subjective symptoms are more unreliable than objective signs in identifying homogenous groups of patients. As a result, groups of patients with dyspepsia who are undergoing treatment are likely to contain some patients who do not have dyspepsia, which may dilute (negatively affect) the results of the treatment. Moreover, the results of treatment must be evaluated on the basis of subjective responses (such as improvement of pain). In addition to being more unreliable, subjective responses are more difficult to measure than objective responses (for example, healing of an ulcer).
• Different subtypes of dyspepsia (for example, abdominal pain and abdominal bloating) are likely to be caused by different physiologic processes (mechanisms). It also is possible, however, that the same subtype of dyspepsia may be caused by different mechanisms in different people. What's more, any drug is likely to affect only one mechanism. Therefore, it is unlikely that any one medication can be effective in all-even most-patients with dyspepsia, even patients with similar symptoms. This inconsistent effectiveness makes the testing of drugs particularly difficult. Indeed, it can easily result in drug trials that demonstrate no efficacy (usefulness) when, in fact, the drug is helping a subgroup of patients.
• Subjective symptoms are particularly prone to responding to placebos (inactive drugs). In fact, in most studies, 20% to 40% of patients with dyspepsia will improve if they receive inactive drugs. Now, all clinical trials of drugs for dyspepsia require a placebo-treated group for comparison with the drug-treated group. The large placebo response means that these clinical trials must utilize large numbers of patients to detect meaningful (significant) differences in improvement between the placebo and drug groups. Therefore, these trials are expensive to conduct.

The lack of understanding of the physiologic processes (mechanisms) that cause dyspepsia has meant that treatment usually cannot be directed at the mechanisms. Instead, treatment usually is directed at the symptoms. For example, nausea is treated with medications that suppress nausea but do not affect the cause of the nausea. On the other hand, the psychotropic drugs (antidepressants) and psychological treatments (such as cognitive behavioral therapy) treat hypothetical causes of dyspepsia (for example, abnormal function of sensory nerves and the psyche) rather than the symptoms. Treatment for dyspepsia often is similar to that for irritable bowel syndrome (IBS) even though the causes of IBS and dyspepsia are likely to be different.

Education

It is important to educate patients with dyspepsia about their illness, particularly by reassuring them that the illness is not a serious threat to their physical health (though it may be to their emotional health). Patients need to understand the mechanisms (causes) for the symptoms. Most importantly, they need to understand the medical approach to the problem and the reasons for each test or treatment. Education prepares patients for a potentially prolonged course of diagnosis and trials of treatment. Education also may prevent patients from falling prey to the charlatans who offer unproven and possibly dangerous treatments for dyspepsia. Many symptoms are tolerable if patients' anxieties about the seriousness of their symptoms can be relieved. It also helps patients deal with symptoms when they feel that everything that should be done to diagnose and treat, in fact, is being done. The truth is that psychologically healthy people can tolerate a good deal of discomfort and continue to lead happy and productive lives.

Diet

Dietary factors have not been well-studied in the treatment of dyspepsia. Nevertheless, patients often associate their symptoms with specific foods (such as salads and fats). Although specific foods might worsen the symptoms of dyspepsia, they are not the cause of dyspepsia. (Intolerance to specific foods, for example, lactose intolerance (milk) and allergies to wheat, eggs, soy, and milk protein are not considered functional diseases. The common placebo response in functional disorders such as dyspepsia also may explain the improvement of symptoms in some people with the elimination of specific foods.

Dietary fiber often is recommended for patients with IBS, but fiber has not been studied in the treatment of dyspepsia. Nevertheless, it probably is reasonable to treat patients with dyspepsia with fiber if they also have constipation.

Intolerance to lactose (the sugar in milk) often is blamed for dyspepsia. Since dyspepsia and lactose intolerance both are common, the two conditions may coexist. In this situation, restricting lactose will improve the symptoms of lactose intolerance, but will not affect the symptoms of dyspepsia. Lactose intolerance is easily determined by testing the effects of lactose (hydrogen breath testing) or trying a strict lactose elimination diet. If lactose is determined to be responsible for some or all of the symptoms, elimination of lactose-containing foods is appropriate. Unfortunately, many patients stop drinking milk or eating milk-containing foods without good evidence that it improves their symptoms. This often is detrimental to their intake of calcium which may contribute to osteoporosis.

One of the food substances most commonly associated with the symptoms of dyspepsia is fat. The scientific evidence that fat causes dyspepsia is weak. Most of the support is anecdotal (not based on carefully done, scientific studies). Nevertheless, fat is one of the most potent influences on gastrointestinal function. (It tends to slow down the gastrointestinal muscles while it causes the muscles of the gallbladder to contract.) Therefore, it is possible that fat may worsen dyspepsia even though it doesn't cause it. Moreover, reducing the ingestion of fat might relieve symptoms. A strict low fat diet can be accomplished fairly easily and is worth trying. Additionally, there are other health-related reasons for reducing dietary fat.

Another dietary factor, fructose and fructose-related sugars, has been suggested as a cause of dyspepsia since many people do not fully digest and absorb them before they reach the distal intestine. It is diagnosed with a hydrogen breath test using fructose and treated with elimination of fructose-containing foods from the diet. Unfortunately, fructose and its related sugars are widespread among fruits and vegetables and are found in high concentrations in many food products sweetened with corn syrup. Thus, an elimination diet is more difficult to maintain.

Psychotropic drugs

Patients with functional disorders, including dyspepsia, are frequently found to be suffering from depression and/or anxiety. It is unclear, however, if the depression and anxiety are the cause or result of the functional disorders or are unrelated to these disorders. (Depression and anxiety are common and, therefore, their occurrence together with functional disorders may be coincidental.) Several clinical trials have shown that antidepressants are effective in IBS in relieving abdominal pain. Antidepressants also have been shown to be effective in unexplained (non-cardiac) chest pain, a condition thought to represent a dysfunction of the esophagus. Antidepressants have not been studied adequately in other types of functional disorders, including dyspepsia. It probably is reasonable to treat patients with dyspepsia with psychotropic drugs if they have moderate or severe depression or anxiety.

The antidepressants work in dyspepsia and in functional esophageal pain at relatively low doses that have little or no effect on depression. It is believed, therefore, that these drugs work not by combating depression, but in different ways (through different mechanisms). For example, these drugs have been shown to adjust (modulate) the activity of the nerves and to have analgesic (pain-relieving) effects as well.

Commonly used psychotropic drugs include the tricyclic antidepressants, desipramine (Norpramine) and trimipramine (Surmontil). Although studies are encouraging, it is not yet clear whether the newer class of antidepressants, the serotonin-reuptake inhibitors such as fluoxetine (Prozac), sertraline (Zoloft), and paroxetine (Paxil), are effective in functional disorders, including dyspepsia.

Psychological treatments

Psychological treatments include cognitive-behavioral therapy, hypnosis, psychodynamic or interpersonal psychotherapy, and relaxation/stress management. Few studies of psychological treatments have been conducted in dyspepsia, although more studies have been done in IBS. Thus, there is little scientific evidence that they are effective in dyspepsia, although there is some evidence that they are effective in IBS.

Hypnosis has been proposed as an effective treatment for IBS. It is unclear exactly how effective hypnosis is, or how it works.

Promotility drugs

One of the leading theories for the cause of dyspepsia is abnormalities in the way gastrointestinal muscles function. The function of muscles may be abnormally increased, abnormally decreased, or it may by uncoordinated. There are medications, called smooth muscle relaxants, that can reduce the activity of the muscles and other drugs that can increase the activity of the muscles, called the promotility drugs.

Many of the symptoms of dyspepsia can be explained on the basis of reduced activity of the gastrointestinal muscles that results in slowed transport (transit) of food through the stomach and intestine. (It is clear, as discussed previously, that there are other causes of these symptoms in addition to slowed transit.) Such symptoms include nausea, vomiting, and abdominal bloating. When transit is severely affected, abdominal distention (swelling) also may occur and can result in abdominal pain. (Early satiety is unlikely to be a function of slowed transit because it occurs too early for slowed transit to have consequences.) Theoretically, drugs that speed up the transit of food should, in at least some patients, relieve symptoms of dyspepsia that are due to slow transit.

The number of promotility drugs that are available for use clinically is limited. Studies of their effectiveness in dyspepsia are even more limited. The most studied drug is cisapride (Propulsid), a promotility drug that was withdrawn from the market because of serious cardiac side effects. (Newer drugs that have similar effects but lack the toxicity are being developed.) The few studies with cisapride for dyspepsia were inconsistent in their results. Some studies demonstrated benefits whereas others showed no benefit. Cisapride was effective in patients with severe emptying problems of the stomach (gastroparesis) or severely slowed transit of food through the small intestine (chronic intestinal pseudo-obstruction). These two diseases may or may not be related to dyspepsia.

Another promotility drug that is available is erythromycin, an antibiotic that stimulates gastrointestinal smooth muscle as one of its side effects. Erythromycin is used to stimulate smooth muscles of the gastrointestinal tract at doses that are lower than those used for treating infections. There are no studies of erythromycin in dyspepsia, but erythromycin is effective in gastroparesis and probably also in chronic intestinal pseudo-obstruction.

Metoclopramide (Reglan) is another promotility drug that is available. It has not been studied, however, in dyspepsia. Moreover, it is associated with some troubling side effects. Therefore, it may not be a good drug to undergo further testing in dyspepsia.

Domperidone (Motilium) is a promotility drug that is available in the U.S., but requires a special permit from the US Food and Drug administration. As a result, it is not very commonly prescribed. It is an effective drug with minimal side effects.

Smooth muscle relaxants

The most widely studied drugs for the treatment of abdominal pain in functional disorders are a group of drugs called smooth-muscle relaxants.

The gastrointestinal tract is primarily composed of a type of muscle called smooth muscle. (By contrast, skeletal muscles such as the biceps are composed of a type of muscle called striated muscle.) Smooth muscle relaxant drugs reduce the strength of contraction of the smooth muscles but do not affect the contraction of other types of muscles. They are used in functional disorders, particularly IBS, with the assumption (not proven) that strong or prolonged contractions of smooth muscles in the intestine-spasms-are the cause of the pain in functional disorders. There are even smooth muscle relaxants that are placed under the tongue, as is nitroglycerin for angina, so that they may be absorbed rapidly.

There are not enough studies of smooth muscle relaxants in dyspepsia to conclude that they are effective at reducing pain. Since their side effects are few, these drugs probably are worth trying. As with all drugs that are given to control symptoms, patients should carefully evaluate whether or not the smooth muscle relaxant they are using is effective at controlling the symptoms. If it is not clearly effective, the option of discontinuing the relaxant should be discussed with a physician.

Commonly used smooth muscle relaxants are hyoscyamine (Levsin, Anaspaz, Cystospaz, Donnamar) and methscopolamine (Pamine, Pamine Forte). Other drugs combine smooth muscle relaxants with a sedative chlordiazepoxide hydrochloride and clidinium bromide (Donnatal, Librax), but there is no evidence that the addition of sedatives adds to the effectiveness of the treatment.