Müller-Lissner Stefan
Humboldt University Berlin, Department of Internal Medicine, Park-Klinik Weissensee, Germany.
Best Pract Res Clin Gastroenterol. 2002 Feb;16(1):115-33. doi: 10.1053/bega.2002.0269.
The incidence of constipation increases with age but no consistent changes of colonic or anorectal motility have been shown in elderly people. Instead, neurological diseases, constipating drugs, bedriddenness and weak straining ability may explain this increased prevalence of constipation. The amount of dietary fibre in the diet may be reduced because of poor chewing ability. Parkinson's disease is accompanied by both slow colonic transit and impaired relaxation of the anal sphincter. Drug-induced constipation is particularly likely with anti-parkinsonism drugs (either anti-cholinergic or dopaminergic) and also with tricyclic anti-depressants, opiates, iron, anti-convulsants and aluminium- or calcium-containing antacids. The prevalence of faecal incontinence is also increased in elderly people. About half of frail bedridden institutionalized patients are incontinent. Anal sphincter pressures tend to be lower, but variables of sensitivity are not. In bedridden people faecal impaction may occur. The ensuing rectal distension leads to relaxation of the internal sphincter and hence to faecal soiling. The condition is often overlooked though correct diagnosis is rather simple, being made with a digital rectal examination.
便秘的发生率随年龄增长而增加，但老年人结肠或肛门直肠运动功能并未显示出一致的变化。相反，神经系统疾病、导致便秘的药物、卧床不起和排便用力能力减弱可能解释了便秘患病率的增加。由于咀嚼能力差，饮食中膳食纤维的量可能会减少。帕金森病既伴有结肠传输缓慢，又伴有肛门括约肌松弛受损。抗帕金森病药物（抗胆碱能或多巴胺能药物）以及三环类抗抑郁药、阿片类药物、铁剂、抗惊厥药和含铝或钙的抗酸剂特别容易导致药物性便秘。老年人粪便失禁的患病率也会增加。约一半体弱卧床的住院患者存在失禁情况。肛门括约肌压力往往较低，但敏感性变量并非如此。卧床患者可能会发生粪便嵌塞。随之而来的直肠扩张会导致内括约肌松弛，进而导致粪便污染。尽管正确诊断相当简单，通过直肠指检即可做出，但这种情况常常被忽视。
