Constipation of anorectal outlet obstruction: pathophysiology, evaluation and management.
ABSTRACT Constipation is a subjective symptom of various pathological conditions. Incidence of constipation fluctuates from 2 to 30% in the general population. Approximately 50% of constipated patients referred to tertiary care centers have obstructed defecation constipation. Constipation of obstructed defecation may be due to mechanical causes or functional disorders of the anorectal region. Mechanical causes are related to morphological abnormalities of the anorectum (megarectum, rectal prolapse, rectocele, enterocele, neoplasms, stenosis). Functional disorders are associated with neurological disorders and dysfunction of the pelvic floor muscles or anorectal muscles (anismus, descending perineum syndrome, Hirschsprung's disease). However, this type of constipation should be differentiated by colonic slow transit constipation which, if coexists, should be managed to a second time. Assessment of patients with severe constipation includes a good history, physical examination and specialized investigations (colonic transit time, anorectal manometry, rectal balloon expulsion test, defecography, electromyography), which contribute to the diagnosis and the differential diagnosis of the cause of the obstructed defecation. Thereby, constipated patients can be given appropriate treatment for their problem, which may be conservative (bulk agents, high-fiber diet or laxatives), biofeedback training or surgery.
Article: Anorectal physiology.[show abstract] [hide abstract]
ABSTRACT: Anorectal physiology, as assessed in an ARP laboratory, can provide helpful information in the management of patients with constipation and bowel incontinence. Beyond the uses described in this review, however, the ARP laboratory is most useful in the research setting. In this setting the laboratory can expand our understanding of function associated with other disease states, including anal fissure, fistula-in-ano, inflammatory bowel disease, and postoperative states. The lab can also provide improved understanding of the complex interactions of the enteric nervous and gut hormone systems with the smooth and skeletal muscle systems. A part of the failure of the ARP laboratory to enjoy more clinical usefulness lies in a lack of standardization of test protocols for many of the tests. Secondarily, there is a lack of normative data from large numbers of normal patients . Finally, there is the difficulty in reproducing tests in situations where the patient has significant potential to compensate for deficits through the recruitment of adjacent muscle groups and other maneuvers. There is also some reluctance on the part of clinicians to make use of the ARP laboratory if the testing is not readily available in their community. Although the tests themselves are not difficult to learn to administer, lack of familiarity with the testing process can act as a barrier to acceptance. This is particularly true for clinicians that are used to making clinical decisions without the added benefit of physiologic testing. Despite these obstacles, the role of the ARP laboratory in the management of complex anorectal disease is likely to grow in the years ahead.Surgical Clinics of North America 01/2003; 82(6):1115-23. · 2.02 Impact Factor
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ABSTRACT: Paradoxical contraction of the puborectalis muscle during simulated defecation straining (anismus) has been cited as a cause of constipation. The functional specificity of this phenomenon was evaluated in 79 patients, 50 with constipation, 21 with idiopathic perineal pain, and eight with solitary rectal ulcer syndrome. Electromyogram evidence of paradoxical puborectalis contraction was observed in 38 (76 percent), ten (48 percent), and four (50 percent) of these patients, respectively. All patients with solitary rectal ulcer syndrome had difficulty defecating; defecation was normal in all patients with perineal pain. These observations suggest that paradoxical contraction of the puborectalis muscle is not a specific finding, and that it is not the sole cause of constipation in patients with anismus.Diseases of the Colon & Rectum 10/1987; 30(9):667-70. · 3.34 Impact Factor
- Colorectal Disease 02/2002; 4(1):67. · 2.08 Impact Factor