怎样治疗长期便秘

如何治疗长期便秘配图，仅供参考

9.2.1 Constipation
Constipation may be a problem in early stages,but is rarely present when IF occurs. In the early stages of these diseases,constipation may be managed by diet ensuring that it includes an adequate intake of fibre and fluid. Bulk forming laxatives such as unprocessed wheat bran (or oat bran) taken with food or fruit juice are effective and methylcellulose (which is also a faecal softener),ispaghula,and sterculia are useful in patients who cannot tolerate bran.
Osmotic laxatives (macrogols (polyethylene glycol),lactulose or magnesium salts) increase the amount of water in the large bowel,either by drawing fluid from the body into the bowel or by retaining the fluid that was administered. Macrogols are inert polymers of ethylene glycol (PEG) which sequester fluid in the bowel. Lactulose is a semi-synthetic disaccharide which is not absorbed from the gastrointestinal tract. It produces osmotic diarrhoea of low pH and prevents the proliferation of ammonia-producing organisms. Magnesium salts are useful where rapid bowel evacuation is required. Sodium salts should be avoided as they may give rise to sodium and water retention.
If there is an inadequate response to an osmotic laxative,a stimulant laxative can be added. Stimulant laxatives increase intestinal motility and often cause abdominal cramp; they should be avoided in intestinal obstruction. Excessive use of stimulant laxatives can cause diarrhoea and hypokalaemia. The anthraquinone laxatives (senna,dantron,cascara) are converted in the intestine to active sennosides,which may function by stimulating the myenteric plexus in the colon and also by inhibiting colonic water absorption. Their principal effect is in the descending and sigmoid colon. Their effect is largely local and depends on sufficient intestinal motility to present them to the colon for bacterial degradation to their active form. Sennosides,with prolonged use,had been thought to damage the intestine muscle and/or myenteric neurons but there is no clinical or animal evidence to support this. [122 123](https://ncbi.nlm.nih.gov/pmc/articles/PMC7677490/#R122) Poorly absorbed diphenylmethane derivatives (bisacodyl,phenolphthalein,sodium picosulfate) stimulate sensory nerves in the proximal colon and increase sodium and water movement into the colonic lumen. Castor oil can have a place with its principal effect on small bowel fluid secretion. Docusate sodium probably acts both as a stimulant and also as a softening agent.
Dantron,cascara and castor oil are rarely used,dantron because of potential carcinogenicity.
5HT4 receptor agonists (prucalopride) are selective serotonin 5HT4 receptor agonists with prokinetic properties. Prucalopride is licensed for the treatment of chronic constipation in women when other laxatives have failed to provide an adequate response. Headache and gastrointestinal symptoms (including abdominal pain,nausea and diarrhoea) are the most frequent but rare side effects. The side effects generally occur at the start of treatment and are usually transient. It has the potential to be a useful prokinetic drug now that cicapride and tegaserod have largely been withdrawn. Linaclotide (a 14-amino acid peptide) which acts in the intestinal lumen on guanylate cyclase-C (GC-C) so generating cyclic guanosine monophosphate (cGMP),which stimulates chloride secretion,resulting in increased luminal fluid secretion and an acceleration of intestinal transit. It also may have some visceral analgesic activity.
Methylnaltrexone is a peripherally acting mu-opioid-receptor antagonist that is licensed for the treatment of opioid-induced constipation in patients receiving palliative care when response to other laxatives is inadequate; it should be used as an adjunct to existing laxative therapy. Methylnaltrexone does not alter the central analgesic effect of opioids. Naloxegol is an oral agent and has the same properties.
Faecal softeners (liquid paraffin),the traditional lubricant,have potential disadvantages of minimal efficacy (hence usually used in combination with other agents) and safety issues (aspiration of paraffin,perianal burning). Bulk laxatives and non-ionic surfactant ‘wetting’ agents (docusate sodium) also have softening properties. Enemas containing arachis oil (ground-nut oil,peanut oil) lubricate and soften impacted faeces and promote a bowel movement. Dioctyl sulfosuccinate,an anionic detergent,can be used to break down hard stools.
Stimulant suppositories (glycerol) or enemas (phosphate) may also be effective although they are often less acceptable to the patient. Glycerol suppositories act as a rectal stimulant by virtue of the mildly irritant action of glycerol. Constipation may need regular enemas initially using low volume phosphate preparations progressing to high volume saline washouts or transanal irrigation systems.
Treatment of faecal impaction may need a manual evacuation under anaesthetic if disimpaction does not occur after oral and rectal treatment,or if there is a megarectum. The outcome of colectomy?ileorectal anastomosis is poor for these patients and best avoided. Sometimes a defunctioning loop ileostomy,which is reversible,may be performed before considering a total colectomy.","department":"