Seminars in gastrointestinal disease最新文献

An increasing amount of evidence indicates that gastroesophageal reflux disease (GERD) is a contributing factor to hoarseness, throat clearing, throat discomfort, chronic cough, and shortness of breath. The association between GERD and these supraesophageal symptoms may be elusive. Heartburn and regurgitation are absent in more than 50% of patients. Acid reflux should be considered if signs of GERD are present, symptoms are unexplained, or symptoms are refractory to therapy. The diagnosis of GERD may be unclear, despite a careful history and initial evaluation. A high index of suspicion is required to make the diagnosis. An empiric trial of antireflux therapy is appropriate when GERD is suspected. Multiprobe ambulatory pH monitoring is currently the diagnostic test of choice, but the level of sensitivity and specificity for supraesophageal manifestations of GERD is uncertain. Response to antireflux therapy is less predictable than typical GERD. More intensive acid suppression and longer treatment duration are usually required.

The recent rapid increase in the incidence of adenocarcinoma of the distal esophagus and the gastric cardia has generated significant interest in the premalignant lesion, Barrett's esophagus. The traditional definition of Barrett's esophagus included the presence of 3 cm or greater of columnar mucosa in the distal esophagus. Studies have clarified that intestinal metaplasia was not only the most common and distinctive type of epithelium detected within the columnar mucosa, but also the one with greatest malignant potential; therefore, Barrett's esophagus has come to be defined by the histological presence of intestinal metaplasia. Previous studies evaluating the association of esophageal adenocarcinoma with Barrett's esophagus have only included patients with traditional or long-segment Barrett's esophagus. However, recent studies have suggested that dysplasia and adenocarcinoma can also be associated with short-segment Barrett's esophagus (SSBE), ie, less than 3 cm of columnar mucosa. Data are also emerging regarding the significance of intestinal metaplasia detected in biopsy specimens obtained immediately below the gastroesophageal junction, ie, from the gastric cardia. However, the premalignant potential of cardia intestinal metaplasia (CIM) is unknown at this time. Although the exact incidence of adenocarcinoma in SSBE is not known, endoscopic surveillance of such patients, although controversial, appears to be prudent at this time. With the currently available information, routine biopsy of a normal-appearing squamocolumnar junction is not advocated. This review critically evaluates and summarizes recent data on SSBE and CIM.

Obscure gastrointestinal bleeding after careful endoscopy of the upper and lower gastrointestinal tract is predominantly of small-bowel origin. Patients presenting with overt blood loss account for a select subpopulation of those with small-bowel bleeding. Although relatively rare, these patients often require repeated blood transfusions, investigation, and hospitalization before a diagnosis is reached. These events have a considerable negative impact on the patient's quality of life. Standard evaluation using enteroclysis, tagged red cell studies, and angiography are proven to be of limited value in this context. Push enteroscopy has significant advantages in this patient group, with the ability to deliver endoscopic therapy. Sonde enteroscopy is now reserved for a few patients to guide decisions on surgery, particularly in those with significant medical comorbidity. Definitive evaluation may require perioperative enteroscopy, but many patients can be managed without the need for surgery. A team approach by physician, radiologist, and surgeon following locally agreed algorithms is essential for the successful management of this challenging clinical problem.

Iron deficiency anemia is the most common form of anemia encountered in clinical practice and is an extremely common manifestation of chronic occult gastrointestinal bleeding. Current evidence suggests that a large proportion of men and postmenopausal women with iron deficiency anemia harbor significant gastrointestinal tract pathological lesions as the source of blood loss. As such, the evaluation of patients with iron deficiency anemia is generally focused on the gastrointestinal tract. Importantly, the diagnosis of iron deficiency anemia should be firmly established before an extensive evaluation is undertaken. Management strategies for patients with iron deficiency anemia are reviewed; an important general point is that clinical features (ie, symptoms) may help direct specific investigation. The role of small-intestinal investigation in patients with iron deficiency anemia is controversial and should probably be reserved for patients with iron deficiency anemia and persistent gastrointestinal symptoms or those who fail to respond to appropriate therapy. The treatment and prognosis of patients with iron deficiency anemia and the majority of gastrointestinal tract lesions are straightforward. However, patients with vascular ectasias as the source of blood loss can represent a true management challenge.

Occult gastrointestinal bleeding is diagnosed by using one of the commercially available fecal occult blood tests (FOBTs). Guaiac-based slide tests are most frequently used, although the more specific immunochemical methods are promising. The guaiac tests are inexpensive, nonspecific, qualitative measures of stool blood, and their use requires dietary and drug restrictions. Clinicians need to be aware of the causes of false-positive and false-negative test results. Although specific for the presence of human blood, immunochemical tests are more expensive and tend to react also to physiological quantities of blood in fecal specimens. Whichever test is chosen, it must be processed and read correctly. Annual FOBT screening for colorectal cancer, combined with periodic flexible sigmoidoscopy, is a cost-effective method of detecting early, curable colorectal cancer.

In this age of modern technology and aggressive but noninvasive therapies, the idea of treating an identifiable but discrete bleeding lesion with systemic medical therapy seems an anachronism. But medical therapy can be the treatment of choice for some bleeding vascular lesions of the gut. Though most vascular lesions appear similar endoscopically and are a cause of gastrointestinal bleeding, they consist of various pathologic identities. These different lesions have not only different pathologic appearances, but also different prognoses. The natural history of many of these lesions remains largely unknown. Long-term success in controlling bleeding must be measured in the context of the responsible lesion's frequency of occurrence and recurrence. Medical therapy can include hopeful watchful waiting, routine blood transfusions, or specific medications. Medical therapy has been pursued along two lines. The most common form of medical therapy has been simple supportive care. This may include iron therapy and avoidance of aspirin and other anticoagulants. Transfusions may be necessary, occasionally or on a regular basis. The second form of medical therapy has been the use of estrogens. There have been other medical attempts to control bleeding from intestinal vascular lesions. Somatostatin has been used in an uncontrolled fashion, as has aminocaproic acid. Vascular lesions of the bowel are not all the same. Medical therapy of vascular lesions is contrary to general present practice. Endoscopic or surgical therapy is presently considered best because of its ease, relatively good long-term results, and the lack of a clearly effective, well-tolerated medical therapy. Medical therapy is usually reserved for diffuse vascular diseases of the bowel, for vascular lesions located in relatively inaccessible locations, for patients with continued bleeding despite endoscopic or surgical management, and for patients who are not candidates for either endoscopic or surgical therapy.

The surgeon is frequently involved in the management of patients with occult gastrointestinal bleeding. It is important to have a systematic approach to these patients to avoid the "looking for a needle in a haystack" approach to this problem. These are a group of patients who have undergone extensive standard gastroendoscopic evaluation and continue to bleed. Five percent of gastrointestinal bleeding occurs between the ligament of Treitz and the ileocecal valve. Therapeutic management may be guided by the age of the patient. Patients aged younger than 50 years will usually bleed from readily identifiable palpable lesions, such as leiomyoma, Meckel's diverticulum, or other small-bowel tumors, whereas the patients aged older than 50 years most commonly bleed from angiodysplasias or arteriovenous malformations that are not palpable, frequently multiple, and may be evanescent.

Gastroenterology has always been a collaborative specialty. Through the years, gastroenterologists have created important partnerships with pathologists, radiologists, surgeons, gynecologists, and pediatricians. These collaborative relationships have greatly enhanced patient care and research. This article reviews the literature on psychiatric comorbidity in the medical setting and gastroenterology practice in particular. The ability to recognize psychiatric comorbidity and relate it to the patient's presenting gastrointestinal (GI) complaint can pay great dividends for patients. The ability to apply these observations to help facilitate psychiatric collaboration and specifically, to initiate behavioral treatment, represents a new dimension in the care of chronic GI disorders. Finally, the relationship between physical and sexual abuse and GI illness and the usefulness of psychiatric interventions in the treatment of chronic GI disorders is reviewed in detail.

Although placebo may be defined as a treatment that does not have a specific effect on the illness for which it is being used, or as an intervention for which there is no scientific theory explaining its mechanism of action, placebo can be an effective therapeutic intervention. Placebo can be administered as a drug or as a procedural intervention. Multiple factors affect the ultimate intensity of the placebo response. One of these factors is the approach taken by the health care provider in administering an intervention. The medical literature is replete with clinical studies showing beneficial results of placebo administration. Physicians should attempt to better understand placebo to harness its beneficial effects, avoid nocebo or negative effects, and maximize the placebo response.

Medically unexplained symptoms occur in up to 50% of new medical out-patients. Health care seeking may not be related to the presence of physical disease but may reflect social problems, psychological disturbance, or frank psychiatric disorder. Management of unexplained physical symptoms depends on the duration of symptoms. If acute, exclusion of physical disease, as well as providing symptomatic care, is a priority. The patient's fears of illness need to be addressed and an explanation in simple terms of the symptoms provided. Adverse life situations should be identified and, where possible, rectified. Psychiatric disorders require appropriate treatment. When symptoms are chronic, conservative management is required to contain the symptoms and avoid iatrogenic problems.