Review article: therapeutic roles of acupuncture in functional gastrointestinal disorders

Acupuncture has been practiced empirically in China for several millennia, and is being increasingly accepted by practitioners and patients worldwide. Functional gastrointestinal disorders are common in clinical gastroenterology. The prevalence of one or more functional gastrointestinal disorders is estimated to be as high as 70% in general population using Rome diagnostic criteria. Since functional gastrointestinal disorders are diagnosed based on symptoms and the exact aetiologies for most of functional gastrointestinal disorders are not completely known, it is not unusual that the treatment for these disorders is unsatisfactory and alternative therapies are attractive to both patients and practitioners. During the latest decades, a considerable number of studies have been performed on acupuncture for the treatment of functional gastrointestinal disorders and underlying mechanisms. In this article, we reviewed available data in the literature on the applications and mechanisms of acupuncture for the treatment of functional gastrointestinal disorders, including functional oesophageal disorders, nausea and vomiting, functional dyspepsia, irritable bowel syndrome, constipation, etc. A summary is provided based on the quality and quantity of published studies regarding the efficacy of acupuncture in treating these various disorders. In addition, the methodology of acupuncture is also introduced.     

Review article: bloating in functional bowel disorders

Bloating is a frequently reported symptom in functional bowel disorders. It usually occurs in combination with other symptoms, but may also occur in isolation. The severity of bloating tends to worsen during the course of the day and improves overnight. Although frequently considered to be a subjective phenomenon, recent studies have shown that bloating is associated with a measurable increase in abdominal girth. The pathophysiology of bloating remains elusive, but the evidence supports a sensorimotor dysfunction of the bowel. The possible mechanisms include abnormal gas trapping, fluid retention, food intolerance and altered gut microbial flora. Further studies are needed to define the sensorimotor abnormalities associated with bloating, which might be segmental and transient rather than generalized and persistent. The lack of understanding of this symptom is paralleled by a limited availability of therapeutic options. Conventional medications used in functional bowel disorders are not helpful and may indeed worsen the symptoms. In future, new drugs with activity against serotonin and kappa receptors, or novel approaches such as the use of exclusion diets, probiotics and hypnotherapy, may prove to be useful.     

Review article: prebiotics in the gastrointestinal tract

BACKGROUND: Prebiotics are short-chain carbohydrates that alter the composition, or metabolism, of the gut microbiota in a beneficial manner. It is therefore expected that prebiotics will improve health in a way similar to probiotics, whilst at the same time being cheaper, and carrying less risk and being easier to incorporate into the diet than probiotics. AIM: To review published evidence for prebiotic effects on gut function and human health. METHODS: We searched the Science Citation Index with the terms prebiotic, microbiota, gut bacteria, large intestine, mucosa, bowel habit, constipation, diarrhoea, inflammatory bowel disease, Crohn's disease, ulcerative colitis, pouchitis, calcium and cancer, focussing principally on studies in humans and reports in the English language. Search of the Cochrane Library did not identify any clinical study or meta-analysis on this topic. RESULTS: Three prebiotics, oligofructose, galacto-oligosaccharides and lactulose, clearly alter the balance of the large bowel microbiota by increasing bifidobacteria and Lactobacillus numbers. These carbohydrates are fermented and give rise to short-chain fatty acid and intestinal gas; however, effects on bowel habit are relatively small. Randomized-controlled trials of their effect in a clinical context are few, although animal studies show anti-inflammatory effects in inflammatory bowel disease, while calcium absorption is increased. CONCLUSIONS: It is still early days for prebiotics, but they offer the potential to modify the gut microbial balance in such a way as to bring direct health benefits cheaply and safely.     

Review article: aspirin and gastrointestinal bleeding

Many animal and human studies have shown aspirin to cause gastric mucosal erosions and enhanced spontaneous microbleeding. Chronic use is associated with uncomplicated gastric ulcer (but not clearly with uncomplicated duodenal ulcer) and with presentation with haematemesis and melaena. Sub-group analysis suggests that the risks of bleeding duodenal ulcer as well as bleeding gastric ulcer (and possibly non-ulcer bleeding) are increased. These data imply that an anti-haemostatic as well as an ulcerogenic effect contributes to such presentation and acute data support this proposition. A broken mucosa and inhibition of thromboxane synthesis both appear to be necessary for bleeding to occur. Aspirin enhances the bleeding associated with mucosal biopsy analogous to its prolongation of the skin bleeding time. Anti-haemostatic properties could account for the apparent increase in presentation with haematemesis and melaena in patients taking low doses of aspirin for cardiovascular prophylaxis. However, acute studies also show aspirin 300 mg to cause a level of mucosal injury which is substantial, though significantly less than with aspirin 600 mg q.d.s. The risk attached to aspirin consumption needs to be kept in perspective. It can be calculated that aspirin use is associated with approximately 700 bleeds per annum in the UK. The relative risk for upper gastrointestinal bleeding is roughly similar to that for non-aspirin non-steroidal anti-inflammatory drugs but those affected are generally younger, in an age group where death from upper gastrointestinal bleeding is very uncommon. In keeping with this and in contrast to non-aspirin nonsteroidal anti-inflammatory drugs, no study has shown increased mortality from aspirin-related upper gastrointestinal complications.     

Review article: anorexia and cachexia in gastrointestinal cancer

In patients with gastrointestinal malignancies, i.e. cancers of the stomach, colon, liver, biliary tract or pancreas, progressive undernutrition can be regularly observed during the course of illness. Undernutrition significantly affects the patients' quality of life, morbidity and survival. Pathogenetically, two different causes are relevant in the development of undernutrition in patients with gastrointestinal cancer. One cause is reduced nutritional intake. This condition is referred to as anorexia and can be worsened by the side effects of cancer therapy. The other cause is the release of endogenous transmitters and/or other products of the tumour leading to the cachexia syndrome, which is characterized by loss of body weight, negative nitrogen balance and fatigue. Cancer anorexia and cancer cachexia may have synergistic negative effects in affecting the patients' status. In this review, current nutritional support strategies with respect to different clinically relevant situations are described. An algorithm of the treatment strategies, including dietetic counselling, oral supplements, enteral and parenteral nutritional support is given. One focus is the approach of nutrition-focused patient care, which shows promising results. In addition, the possibilities of pharmacological intervention are discussed.     

Review article: olestra and its gastrointestinal safety

Olestra is a fat substitute made from sucrose and vegetable oil. Olestra is neither digested nor absorbed, and therefore adds no calories or fat to the diet. Because the gut is the only organ that is exposed to olestra, the potential for olestra to affect gastrointestinal structure and function, and the absorption of nutrients from the gut, has been investigated. Histological evaluations performed after long-term feeding studies have shown no indications that olestra causes injury to the gastrointestinal mucosa. Olestra is not metabolized by the colonic microflora, and has no meaningful effects on the metabolic function of these organisms. Studies of gastrointestinal transit have shown that the consumption of olestra with food does not affect gastric emptying, or small or large bowel transit times. Olestra does not affect the absorption of macronutrients, water-soluble vitamins or minerals. It causes a dose-responsive decrease in the availability of the fat-soluble vitamins A, D, E and K; however, this potentially adverse effect is offset by the addition of vitamins to olestra-containing foods. Olestra has no consistent effect on the amount of total bile acids excreted in the faeces, and therefore probably has no significant effect on bile acid absorption. The occurrence of gastrointestinal symptoms, including diarrhoea, loose stools, gas and abdominal cramping, after consumption of olestra under ordinary snacking conditions is comparable to that following consumption of triglyceride-containing snacks.     

Review article: the gastrointestinal complications of myositis

Aliment Pharmacol Ther 31 , 359–365

Summary

Background The inflammatory myopathies are a group of acquired diseases characterized by a proximal myopathy caused by an inflammatory infiltrate of the skeletal muscle. The three major diseases are dermatomyositis, polymyositis and inclusion body myositis. Aims To review the gastrointestinal manifestations of myositis. Methods Over 110 articles in the English literature were reviewed. Results Dysphagia to solids and liquids occurs in patients with myositis. The pharyngo‐oesophageal muscle tone is lost and therefore patients develop nasal speech, hoarseness, nasal regurgitation and aspiration pneumonia. There is tongue weakness, flaccid vocal cords, poor palatal motion and pooling of secretions in the distended hypopharynx. Proximal oesophageal skeletal muscle dysfunction is demonstrated by manometry with low amplitude/absent pharyngeal contractions and decreased upper oesophageal sphincter pressures. Patients exhibit markedly elevated creatine kinase and lactate dehydrogenase levels consistent with muscle injury. Myositis can be associated with inflammatory bowel disease, coeliac disease and interferon treatment of hepatitis C. Corticosteroids and other immunosuppressive drugs comprise the mainstay of treatment. Inclusion body myositis responds poorly to these agents and therefore a myotomy is usually indicated. Conclusion Myositis mainly involves the skeletal muscles in the upper oesophagus with dysphagia, along with proximal muscle weakness.     

Review article: the non-inherited gastrointestinal polyposis syndromes

The non-inherited gastrointestinal polyposis syndromes represent a group of rare disorders characterized by the presence of multiple, non-adenomatous polyps on the gastrointestinal mucosa occurring in unrelated patients. We present here a review of the clinical and histo- pathological aspects of the syndromes to include the Cronkhite-Canada syndrome, hyperplastic polyposis and lipomatous polyposis. While infrequently encountered, these diseases can have devastating clinical effects that may be aggravated by delays in diagnosis and treatment. Prompt accurate diagnosis and treatment of these uncommon disorders depend on a sound working knowledge of the distinct clinical and pathological features described herein.     

Review article: non-steroidal anti-inflammatory drug-induced gastrointestinal permeability

Non-steroidal anti-inflammatory drugs induce damage throughout the entire gastrointestinal tract. Administration of site-specific permeability probes is a non-invasive technique for assessing the functional integrity of the gastrointestinal mucosa. A systematic search for NSAID-induced permeability studies using MEDLINE and EMBASE, and an analysis of the literature on NSAID-induced gastrointestinal permeability, were carried out. The advantages and disadvantages of the various probes and study protocols are discussed.
Identification of the underlying mechanisms of regulatory control of the epithelial tight junction is still needed. A greater appreciation of the pharmacokinetics and distribution of NSAIDs, coupled with gastrointestinal permeability studies, may help delineate the pathogenesis of NSAID-induced gastrointestinal toxicity. Non-invasive tests of gastric, intestinal and colonic permeability have shown promise in both basic research and in clinical practice. While such tests could not replace endoscopy, they may represent clinically useful techniques for identifying patients who would benefit from endoscopy, to assess the response to treatment, and perhaps to predict the clinical course of disease.     

Review article: current status of gastrointestinal carcinoids

Carcinoid tumours are enigmatic, slow growing malignancies which occur most frequently (74%) in the gastrointestinal tract. In recent years, it has become apparent that the term 'carcinoid' represents a wide spectrum of different neoplasms originating from a variety of different neuroendocrine cell types. Carcinoid lesions are usually identified histologically by their affinity for silver salts, by general neuroendocrine markers, or more specifically by immunocytochemistry using antibodies against their specific cellular products. Within the gut, the most frequent sites are the small bowel (29%), the appendix (19%) and rectum (13%). Clinical manifestations are often vague or absent. Nevertheless, in approximately 10% of patients the tumours secrete bioactive mediators which may engender various elements of characteristic carcinoid syndrome. In many instances the neoplasms are detected incidentally at the time of surgery for other gastrointestinal disorders. The tendency for metastatic spread correlates with tumour size, and is substantially higher in lesions larger than 2.0 cm. An association with noncarcinoid neoplasms is ascribed in 8-17% of lesions. Treatment consists of radical surgical excision of the tumour, although gastric (type I and II) and rectal carcinoids may be managed with local excision. Overall 5-year survival is excellent for carcinoids of the appendix (86%) and rectum (72%), whereas small intestinal (55%), gastric (49%) and colonic carcinoids (42%) exhibit a far worse prognosis.     

Review article: abdominal bloating and distension in functional gastrointestinal disorders--epidemiology and exploration of possible mechanisms

Background A sensation of abdominal bloating, sometimes accompanied by an increase in girth (distension), is one of the most common and most intrusive features of functional bowel disorders. Aim To conduct a systematic, evidence‐based review of the epidemiology and pathophysiology of abdominal bloating and its relationship to distension. Methods The terms bloating, distension, functional bowel, irritable bowel syndrome, constipation and diarrhoea were searched on MEDLINE up to 2006. References from selected articles and relevant abstracts were also included. Results Approximately 50% of irritable bowel syndrome patients with bloating also experience an increase in abdominal girth and this is more pronounced with constipation than diarrhoea. Bloating appears to be more frequently associated with visceral hypersensitivity, whereas distension is more often related to hyposensitivity and delayed transit. Although there is little evidence for excessive gas as a cause of bloating, gas infusion studies suggest that handling of gas may be impaired in irritable bowel syndrome and there may also be abnormal relaxation of the anterior abdominal musculature in these patients. Conclusions There is unlikely to be a single cause for bloating and distension, which probably have different, but overlapping, pathophysiological mechanisms. Relieving constipation might help distension, but the treatment of bloating may need more complex approaches involving sensory modulation.