Constipation was for a long time defined as prolonged retention of intestinal contents in the intestinal tract or delayed emptying of thickened stool. Defecation frequency, however, is subject to individual variations. Based on old studies in cannery workers and general practice patients without gastrointestinal diseases, a thrice daily to thrice weekly bowel habit is considered „normal“.
There is not necessarily a correlation, however, between defecation frequency and the diagnosis of constipation. Aspects such as pain or difficulty with evacuation are of considerable significance, as are hard stools or a sensation of incomplete rectal emptying.
Constipation can be assumed to be present if
straining is necessary
hard or lumpy stools are present
here is a sensation of incomplete rectal emptying
and there are two or less bowel habits per week
for at least 25 % of the time and for a period of at least 12 months without the use of laxatives.
These are scientific definitions, however, which often have little in common with everyday medical experience and may not reflect patients' subjective perceptions.
Pathophysiology
We can differentiate between at least eight types of constipation:
Chronic habitual obstipation as a functional disorder:
most common form, occurs in 10% of the population of industrialised countries because of:
- Low-fibre diet, insufficient intake of fluids
- Insufficient movement and suppression of the urge to evacuate.
Obstipation in the case of irritable bowel syndrome
Transitory or situative constipation in cases of feverish illnesses, bed confinement, change of diet on trips, etc.
Medicinally-induced obstipation
Electrolyte disturbances:
- Hypokalemia (often a result of a laxative abuse, vicious circle!)
- Hyperkalemia
Obstipation in cases of organic intestinal diseases:
- Obstruction or stricture: adenoma, carcinom stenosing diverticulitis, rectocele, hernia, compression, foreign bodies etc.
- Inflammable intestinal diseases: Divertikulitis, M. Crohn etc.
- Anal diseases: fissures, abscesses, painful haemorrhoids etc.
Neurogenic disturbances, e. g., diabetic autonomous neuropathy, Parkinson's disease, Multiple Scleroses, Hirschsprung's disease (aganglionosis of the rectum)
Endocrine causes: Hypothyreosis, pregnancy
Finally, there are also indications of a weak hereditary background.
A range of medicines can cause obstipation as a side effect, e. g.:
Amitriptyline
Antazida (with aluminium or calcium)
Anticholinergics
Tricyclic antidepressants
Non-steroid anti-inflammatory drugs
Barium sulphate
Cholestyramine
Clonidine
Colestipol
Disopyramide
Diuretics
Iron
Calcium antagonists
Opioids
Phenothiazine
Phenytoin
Propantheline
Scopolamine
Sucralfate
Sympathomimetics
Vincristine
Bismuth
Low dietary fibre and fluid intake may contribute to the development of constipation, but it remains to be established on an individual basis whether suitably compensating such deficiencies can initially be regarded as initially adequate, or whether a safe and well tolerated laxative to be given for a certain period should also be prescribed from the outset.
A wide variety of treatment modalities are available for the management of constipation: increased dietary fibre and fluid intake is consistently recommended as the basic therapy. Considering the major difficulties involved in achieving a lasting dietary modification, the success of such measures is often unsatisfactory and merely temporary.
As a consequence, laxatives are frequently used, either on prescription or as self medication. Available laxatives are classified into various groups according to their different mechanisms of action:
lactulose
lubricants (especially liquid paraffin)
bulking agents (bran, seeds, synthetic materials)
osmotic laxatives (non-absorbable salts and sugar alcohols)
irritant laxatives (anthranoids and diphenylmethane derivatives)
prokinetics
Constipation management thus encompasses a broad range of therapeutic op-tions, but the appropriate modality should be judiciously selected under drug safety aspects. Irritant laxatives in particular are commonly abused, and there is also increasing evidence that their active ingredients, the anthranoids, may be carcinogenic, which has led the highest health authority to officially restrict their use.
Duphalac® is still usually classified in the group of osmotic laxatives. This is only partially correct.
Duphalac® is a nondigestible disaccharide. It is thus the shortest conceivable form of nondigestible oligo- (poly-) saccharides (bulking agents) and is in many respects comparable to these substances, all of which are commercially available as foods or food additives. Some are simultaneously and undisputedly medicinal products and food additives (sorbitol, mannitol). Duphalac® was first classified as a drug because of the time at which it was developed and is therefore subject to other assessment criteria.
In 1959, Mayerhofer and Petuely published the first report on the use of Duphalac® for the treatment of constipation and, like other investigators, particularly recommended it as a safe laxative for children.
Numerous studies have since been conducted on the effectiveness of Duphalac® in the management of constipation. Duphalac® has been proven to work gently and safely, even for special patient groups who cannot be treated with laxatives or treated over a prolonged period.
