我们认为在1970年代患有IBS的患者中有三分之二可以诊断为胆汁酸腹泻等可治疗的疾病,炎症性肠病,显微镜下结肠炎,乳糜泻,二糖吸收不良,胰腺外分泌功能不全,或罕见的遗传变异。尽管诊断技术取得了进步,但仍有很大一部分患者继续患有IBS样症状,这无法通过现有知识来解释。尽管进一步的研究可能会发现具有IBS样症状可治疗机制的患者的小而重要的亚组,我们建议临床上只需要解决两个大的群体:患有结缔组织疾病的患者,如Ehlers-Danlos综合征或高移动性谱系障碍的患者,以及患有自闭症谱系障碍的患者.结缔组织疾病患者表现出可识别的肠道运动功能紊乱,并可能增加肠道通透性,这是IBS样症状的潜在机制。自闭症谱系障碍在临床上提出了一个更加困难的问题。感知的干扰加上焦虑和对肠道信号的过度担忧,可能导致无休止但徒劳的寻找错误。搜索可能涉及大量护理人员,没有人理解病人的痛苦。其他人可能会尝试改变饮食以减轻症状,结果发现,几乎所有的食物都可能引起人们对肠道的担忧。早期识别自闭症谱系障碍对于找到更好的方法来帮助胃肠道疾病患者至关重要,通常情况下,肠外症状.
Two thirds of the patients we believed to have IBS in the 1970\'s have since been possible to diagnose with treatable conditions like bile acid diarrhea, inflammatory bowel disease, microscopic colitis, celiac disease, disaccharide malabsorption, exocrine pancreatic insufficiency, or rare genetic variants. Despite advances in diagnostic techniques a substantial proportion of patients continue suffering from IBS-like symptoms that cannot be explained by current knowledge. Although it is likely that further research will reveal small but important subgroups of patients with treatable mechanisms for IBS-like symptoms, we propose that only two large groups remain for being addressed in the clinic: those with connective tissue disorders such as Ehlers-Danlos syndrome or hypermobility spectrum disorders and those with autism spectrum disorders. Patients with connective tissue disorders exhibit identifiable disturbances of gut motor function and possibly increased gut permeability as underlying mechanisms for IBS-like symptoms. Autism spectrum disorders pose a much more difficult problem in the clinic. Disturbances of perception combined with anxiety and excessive worry about signals from the gut can lead to an endless but futile search for something being wrong. The search can involve large numbers of care givers, no one understanding the patient\'s suffering. Others may try to change their diet to lessen symptoms, only to find that almost all foods may cause worrying perceptions from the gut. Early recognition of autism spectrum disorders is essential for finding better ways to help patients with gastrointestinal and, as is often the case, extraintestinal symptoms.