Epidemiology
Most of the available data on IBS come from the West: – Between 10% and 20% of the population are affected, with the female to male ratio at 1.5 to 2.0.
– In a population-based cross-sectional survey conducted in 1999 by a team from the National University of Singapore, where 2,276 people were interviewed in their homes, IBS was found to affect about 1 in 10 people.
– Women between 20 and 40 years of age had the highest frequency (16%) and men aged 50 years and above had the lowest (5%). Interestingly, well-educated women (those with a secondary and tertiary education, comprising 14% of those surveyed) were at high risk for IBS and less well-educated men (those with a primary education, constituting less than 5% of the population surveyed) were at low risk.
– Among patients consulting general practitioners for abdominal symptoms, 30% had IBS; for those consulting specialists (gastroenterologists), the incidence was 21%. IBS together with functional dyspepsia, a related condition, accounted for almost half the consults. – The ratio of female to male patients was 1.5:1
由于肠胃道易激惹综合症(IBS)的病症与其他疾病如结肠炎，憩室病，胃溃疡甚至癌症相似，故必须咨询医生，以求证实。
流行病学 IBS
的资料多来自西方，约有10%至20%的人口患上此病。其中女性与男性的比例为1.5到2.0比1。一九九九年，一组新加坡国立大学进行的抽样人口考察对 2,276人进行家访，发现10人中有一人患上IBS，20到40岁的女性占大多数（16%）五十岁以上的男性为数最少（5%）。有趣的是，受高深教育的女性（中学和大学教育，占受查勘者的14%）患率甚高。反之，受低教育的男性（小学教育，占接受查勘者的5%）患上 IBS 的病率也低。
有肠胃病症状而去求医於普通医生者，30%患有IBS，求医於肠胃专科医生的病人中，有21%是IBS患者，而其中有将近一半的患者有IBS兼机能消化不良，女性病患与男性病患的比例为1.5:1。
Symptoms
Patients with IBS usually experience abdominal pain or discomfort associated with diarrhoea or constipation; some may alternate between diarrhoea and constipation.
In Singapore, about 13% of patients have diarrhoea-predominant IBS and 51% have constipation-predominant IBS.2 Abdominal pain can occur anywhere in the abdomen, even in the so-called “stomach” or gastric area and pelvic area. Patients may also experience feelings of abdominal discomfort, such as bloating, stretching, tightness. Some may have confusing symptoms, such as backache and chest discomfort, as irritation of the bowel can give rise to pain in these
areas.
Diarrhoea associated with IBS is not necessarily severe, as some patients have only two or three bowel movements a day and stools are usually loose but not watery. More disturbing for the patient is the associated urgency. This is when the patient feels the urge to defecate and has to rush to find a bathroom to avoid an accident. Quite often, this occurs when the patient is eating out and it can be embarrassing. Some patients have a particularly unfortunate combination of a weak anus muscle and a sensitive bowel so that they are unable to control and may have accidental leakage.
Other patients experience constipation, with some having a bowel movement once in 3 days or even once a week. These patients can experience a great deal of discomfort when they have not had a bowel movement. This can range from pain to bloating to poor appetite. Some spend a long time in the bathroom and strain, using a lot of effort to produce very small, pellet-like stools.
Incomplete emptying
Many patients have disturbed defecation. Some may have a feeling of incomplete defecation–the sensation that the bowels have not been completely emptied after a bowel movement. This is often frustrating, as the patient must keep going back to the bathroom to make unproductive attempts. At other times, it is disruptive to work or travel as the patient must interrupt an activity to find a bathroom.
Gas and bloating
Some patients may have only mild bowel disturbances and are more bothered by symptoms which they attribute to gas. They may complain of bloating, stomach fullness, a feeling of stretching in the abdomen, flatulence or a noisy, rumbling stomach. Some may not pass much gas, but wish that they could.
Other Symptoms
IBS patients may even experience symptoms seemingly unrelated to the bowels. These can include “gastric”; symptoms, such as heartburn and frequent belching.7 Some also experience problems with urination; they have an irritable bladder in addition to their irritable bowel. Just like their bowels, they may have a frequent urge to pass urine, or feel that they have not completely emptied their bladder even after passing urine and keep returning to the bathroom.6 Some women with IBS may experience pain during sexual intercourse.
IBS symptoms may be confused with other conditions. Patients who experience pain in their upper right side, associated with bloating and frequent belching, may be told that their symptoms are due to gallstones.8 The confusion arises because many patients who have gallstones actually do not have any symptoms from the gallstones. In fact, about 75% of people with gallstones do not feel any pain or discomfort. The gallstone is actually an incidental finding. The pain from IBS can also be mistaken for appendicitis, if it occurs in the lower right corner of the abdomen.9 Women with IBS often think their lower abdominal pain comes from a problem in the uterus or ovaries.10 This is because the symptoms of IBS can be affected by the menstrual cycle,11 bloating and abdominal pain from IBS worsen during menses. Many women find that their constipation is particularly bad during the week before their menses, others may get loose stools during their menses.
病症
腹泻IBS 病人的腹泻问题多不严重，有些病人一天里只如厕2至3次，粪便多松软但不水泄。扰乱病人的是上厕所的急迫性。病人必须尽快找到厕所，否则意外会发生。经常，病人在外用餐发生这种情形，可真难为情。有些病人特别不幸，兼有肛肌无力和敏感性的肠胃，以致失控而导致外漏。
便秘有些病人却经历便秘的不适。有的3天甚至一个星期才排粪一次。这些病人由于肠胃不通而得忍受各种痛楚，从疼痛，腹胀到失去胃口等。有的病人上厕所时，费时又费力，只排出一些硬粪粒。
排便不清许多病人的排便情况被扰乱了。有些则有排便未清的感觉，必须连续上厕所却无所作为，受尽挫折之苦。有时病人不论在工作中或旅行中，必须中止活动而找洗手间，甚为不便。
胃气胀有的病人因肠道问题而受的困扰不大，但为了多种和气有关的病症而烦恼。他们控诉胃气涨，胃感觉饱涨，腹部彭胀感，肠胃气胀而引起咕咕声，但愿能把气体排去。
其他病症 IBS 患者甚至会有其他与肠胃无关的病症，这可能包括胃病的症状，例如胃灼热，经常呃气，有些还有排尿的问题。除了肠道易激惹，还有过敏性的膀胱，和他们的过敏性肠道相似他们经常有要排尿的欲望，或者觉得排尿后膀胱还不清，而要重返洗手间。有些女性患者还会于性交时感觉疼痛。
IBS病症可能会与其他病情混淆。病人因肠胃气胀，经常呃气而引起肚子右上部疼痛，会被误诊为胆石。搞错的原因是由于许多胆结石病人并没有症状。约有70%的胆石病人不觉得任何病痛或不适。其胆石多是在无意中被发现的。IBS的病痛如果是在肚子右下部，也可能被诊断为盲肠炎。女性患者经常以为她们下腹部的疼痛是子宫或卵巢的问题，这是由于IBS的症状会受经期的影响。在月经期间，IBS病情的气胀和腹痛会恶化，许多女性的便秘问题，在月经前一星期特别严重，有些却在月经期间粪便松软。
What causes IBS?
The causes of IBS can be divided into precipitating and aggravating factors. For most patients it is very difficult to pinpoint the precipitating event because it happened a long time ago. The following may precede the onset of IBS.
• Food poisoning or gastroenteritis is the most obvious risk factor for IBS. About 20% to 30% of IBS cases may start this way.12 Depending on severity, 10% to 30% of people who have food poisoning may develop IBS, usually diarrhoea-predominant IBS.
• Surgery in the abdomen, such as a hysterectomy or cholecystectomy.14A hysterectomy is an operation to remove the uterus or womb. The risk is probably low (less than 10%) and affected women usually develop constipation-predominant IBS. A cholecystectomy is an operation to remove the gallbladder. Some patients develop frequent diarrhoea after this type of operation.
• Severe stress in the form of a major life event, such as loss, separation or trauma, can in some cases precede the development of IBS.12 • Other possible causes of IBS include inflammatory bowel disease, a change in diet and the use of antibiotics.15,16,18 Contrary to popular belief, lack of fibre intake does NOT cause IBS.
IBS的起因？
IBS的起因可分成两大因素：急性的和逐渐恶化的，后者因为事情发生太远了，多数病人不能指出使病情恶化的因素，以下几点可能导致IBS的发起：
食物中毒或肠胃炎是最明显的诱发因素，约有20%或30%的IBS个案是由此而引起的。根据个别病情的严重性，10%到30%的病人得了食物中毒后引发IBS，通常为腹泻型IBS。
腹部手术如子宫切除术或胆囊切除术后。子宫切除术后得的IBS风险低（少于10%），但病人通常会引发便秘型的IBS。胆囊切除术后，有些病人会引发腹泻。
生命中发生重大事件，例如亲友的失散，精神或心里的创伤，都会引发IBS。其他可能引起IBS的因素有肠炎性的疾病，饮食的改变，以及服用抗生素等。许多人认为，缺少纤维会引起IBS，其实却不尽然。
Aggravating factors
Aggravating factors for IBS include sleep disturbances, chronic stress, menstruation, antibiotics and certain foods. A survey of 118 female nurses working at major hospital in Singapore, the National University Hospital, helps to illustrate how a combination of factors such as a stressful job and sleep deprivation could make a person more prone to IBS.
Overall about 30% of these nurses had IBS, which is higher than what we observed in the general population. The rate was higher among nurses working on night shifts (38%) compared with nurses on regular hours (20%). Several studies, including the NUH survey mentioned earlier, show that sleep deprivation gives rise to bowel disturbance. In the West, foods that have been implicated in worsening of IBS symptoms are milk and dairy products18, cereals (eg, bran, muesli), grains (eg, wheat, rye, oats) and certain sugars (eg, lactose, fructose, sorbitol). In the past, it was thought that increasing fibre intake by eating more cereals was advisable for patients with IBS. However, new studies have emerged showing the opposite, ie, most patients with IBS actually worsen (55%) on a bran diet and only 10% benefit from it.
In Singapore, curry, chili and coffee were the foods most patients felt worsened their IBS pain.
使病情恶化的因素IBS 恶化的因素还包括睡眠被干扰，延续性的压力，经期，抗生素，某些食物等等。曾经对新加坡一所主要医院即国大医院的118名女护士作过考察，发现综合各种因素如工作压力和睡眠被剥夺等，有较高倾向患IBS，约有30%被考察的护士患上IBS，这比普通人为高。而必须轮夜班的护士的比例，高于做日班者。两者分别为38%至20%。曾作过的多个研究包括先前对国大医院的考察，都发现被剥夺睡眠会引起肠胃不适。西方国家里，会激引病情恶化的食物包括牛奶，奶制品，榖物（如糠，麦，黑麦，燕麦等）以及某些糖类（如乳糖，果糖，山梨糖醇）。过去认为，增加摄取富含纤维的食物，会对IBS病者有助。但根据最新的研究，发现刚好相反。IBS病患食用含高纤维的饭食，多数病情恶化（55%），只有10%的病患受益。在新加坡，病患由于咖厘，辣椒和咖啡等食物而使病情加剧。
Natural history
Most people with IBS experience intermittent symptoms: they will have good times and bad times. A small number have symptoms only once in a long while, others suffer every day. It has been estimated that in 1 year 5% to 30% of people with IBS will lose their symptoms. However, during this time an equal number of people who did not have the condition will develop it, so that the number of people with IBS is kept relatively constant. It is thus projected that most people will experience IBS at some time in their lives.21 For some, symptoms may change with time. In about 22% cases, bowel disturbances become less prominent and the pain and discomfort centres in the upper abdomen.22 When IBS patients were followed up for more than 5 years, less than 5% developed a more serious abdominal condition.
IBS的进展许多IBS患者都有断续的症状: 他们时好时坏。一小部份的症状很久才一次，一些每天都得忍受。估计在一年内有5%至30%的IBS患者的症状会消失。然而，就在同一时期会有相等数量的人开始发现症状，这导致IBS患者的数目一直维持在一定的水平。这显示大部份人的一生中都会在某一段时期经历IBS症状。某一些人的症状会有所变动。在大约 22%的例子里，他们的肠胃不适变得不太明显而这些不适反而集中到腹部上端。在那些IBS超过5年以上复诊的患者里，少过5%的腹部不适会恶化。
Treatment
Diet and maintaining proper eating habits can reduce the symptoms of IBS in some cases. Reducing intake of high-fat foods, alcohol, caffeine, avoiding artificial sweeteners, eating more frequent and smaller meals and keeping a diary of foods that aggravate symptoms may help. Exercising regularly and managing stress can also help. The colon is partly controlled by the nervous system and stress can stimulate spasms in the colon. Using standard relaxation techniques, one can help avoid or limit the colon spasms leading to IBS symptoms. Aromatherapy, yoga, warm showers, massage or a back rub, rest or sleep, stress-management workshop, talking to a friend or even joining a support group can help relieve stress.
Drugs used in the treatment of IBS fall into several categories. Antispasmodics are used to treat abdominal pain by relieving the spasms in the muscles of the intestines. Laxatives are drugs used to treat constipation. Antidiarrhoeal drugs are used to treat diarrhoea. While these drugs may be useful in relieving specific symptoms, their effectiveness in treating IBS is limited. Most of the drugs used in the past were not subjected to rigorous testing, and it now appears that some of them may be no more effective than placebo. Many of the drugs focus on relieving the predominant symptom. Often their effectiveness is limited by side effects. For example, antispasmodic drugs that treat abdominal pain by relaxing the intestine tend to cause constipation. Also, laxatives that stimulate the bowels to move, could cause abdominal cramps due to contractions.
In recent years, more resources and attention have been given to developing effective drug treatments for IBS. Drug companies have invested large sums of money in developing new drugs that meet the stricter requirements of governmental health agencies. For example, the Food & Drug Administration in the US requires that new drugs be approved for treatment of IBS only after rigorous scientific testing shows them to be safe and more effective than placebo. There is now at least one new drug approved by the FDA after undergoing this process.
The best way to control IBS symptoms is to develop with your doctor a program that encompasses all of the above-mentioned, that is, diet and exercise programs, stress management techniques, and medication. It takes constant vigilance to keep track of your symptoms and maintain a proper diet, but the rewards of reduced symptoms and a better quality of life are well worth the effort.
It is also extremely important to maintain open communication channels with your doctor, nurse, pharmacist, or any other healthcare professional with whom you discuss your IBS symptoms. Be honest and thorough in describing your condition so that a correct diagnosis can be made. Finally, if you find that you need help managing your IBS symptoms, do seek out companionship and advice from an IBS support group.
治疗在某一些例子里，节食和保持饮食均衡可以减低IBS症状。减少高脂肪的食物，酒精，咖啡因，避免人造糖，少量多餐以及记下那些会激发症状的食物也有帮助。定期运动和制服压力也有帮助。人体内有一部份的结肠是被神经系统控制，所以压力能引发结肠抽筋。应用简单的放松技巧，就能预防或减少能导致IBS症状的结肠抽筋。香料薰法，瑜伽，温沐浴，按摩或背按摩，休息或睡觉，压力处理讲座，与朋友交谈或参加互助小组也能帮助减轻压力。
治疗IBS 的药物分成几项。止痉挛药是借着减轻小肠肌肉抽筋而得以治疗腹痛。泻药是用来治疗便秘。防泻药是用以防止腹泻。虽然这些药物可以减轻某一方面的症状，但是对于治疗IBS的效果却很有限。以往所用的大部份药物都没加以实验，所以如今发现到这些比代替品（宽心丸）更无效。很多这种药物只是用来集中在减轻初期的症状。往往却因为副作用而不能发挥作用。例如，用来减轻小肠肌肉抽筋而得以治疗腹痛的止痉挛药能导致便秘。还有，用来通便的泻药能导致腹部抽筋而疼痛。
近年来，更多资源和注意力转去制造更有效的IBS治疗药物。药剂厂已投下一笔可观的数目为着制造更有效的新药，一方面也可满足卫生部严格的要求。例如，美国的食品及药物管理局要求新药经过严格的实验，并能证明的确是比代替品（宽心丸）更安全和有效之后才被批准用于治疗IBS。如今最少有一种已经被食品及药物管理局批准的新药，这药物是经过食品及药物管理局严格的实验要求的。
控制IBS症状最好的方法就是与你的医生策划出一项包含以上所提的，那就是节食和运动，压力处理和药物治疗。还需要记录你的症状和保持饮食均衡，这些都要有持之以恒的心态才得以降低症状而提高生活素质。
还有最重要的就是必须与你的医生，护士，药剂师或任何保健专家维持良好的消息传达管道以检讨你的IBS症状。在描述自己的症状时应该坦白，因为这将会对IBS症状有更准确的诊断。最后，如果你的IBS症状需要任何的协助，请向IBS互助小组寻求。
IBS 病患者经常经历便秘或腹泻，或两者交替发生的问题，从而产生肚子痛或腹部不适的感觉。在新加坡，约13%的病人主要是腹泻IBS患者，而51%是便秘 IBS患者。疼痛可发生于肚子任何地方，甚至在胃部或骨盆。病人还会经历肠胃不适，如腹胀，腹抽紧的感觉，有些会有较复杂的病症如背痛或胸部不舒服，这都 是由于肠的激惹而引发的。
