Chronic idiopathic slow transit constipation: pathophysiology and management

Idiopathic Slow Transit Constipation: Pathophysiology, Diagnosis, and Management

Slow transit constipation (STC) has an estimated prevalence of 2-4% of the general population, and although it is the least prevalent of the chronic constipation phenotypes, it more commonly causes refractory symptoms and is associated with significant psychosocial stress, poor quality of life, and high healthcare costs. This review provides an overview of the pathophysiology, diagnosis, and management options in STC. STC occurs due to colonic dysmotility and is thought to be a neuromuscular disorder of the colon. Several pathophysiologic features have been observed in STC, including reduced contractions on manometry, delayed emptying on transit studies, reduced numbers of interstitial cells of Cajal on histology, and reduced amounts of excitatory neurotransmitters within myenteric plexuses. The underlying aetiology is uncertain, but autoimmune and hormonal mechanisms have been hypothesised. Diagnosing STC may be challenging, and there is substantial overlap with the other clinical constipation phenotypes. Prior to making a diagnosis of STC, other primary constipation phenotypes and secondary causes of constipation need to be ruled out. An assessment of colonic transit time is required for the diagnosis and can be performed by a number of different methods. There are several different management options for constipation, including lifestyle, dietary, pharmacologic, interventional, and surgical. The effectiveness of the available therapies in STC differs from that of the other constipation phenotypes, and prokinetics often make up the mainstay for those who fail standard laxatives. There are few available management options for patients with medically refractory STC, but patients may respond well to surgical intervention. STC is a common condition associated with a significant burden of disease. It can present a clinical challenge, but a structured approach to the diagnosis and management can be of great value to the clinician. There are many therapeutic options available, with some having more benefits than others.

Diverting Loop Ileostomy in the Management of Medically Refractory Constipation Cases Not Falling Into Classical Categories

BACKGROUND

The approach to constipation refractory to medical management does not necessarily follow classical teaching and is challenging. Although the role of surgery is unclear, diverting loop ileostomy may be offered to gauge symptom response followed by colectomy for appropriate patients.

OBJECTIVE

Our goal was to examine outcomes in patients with constipation not falling into classical subtypes who underwent diverting loop ileostomy creation as the initial surgical intervention. Our secondary aim was to offer patients colectomy and anastomosis and examine their outcome if they improved after ileostomy.

DESIGN

The study design was a retrospective review.

SETTINGS

This study was conducted in the pelvic floor center of our colorectal surgery department from January 2006 to December 2018.

PATIENTS

Patients with medically refractory constipation referred for surgical consideration and not falling into classical constipation categories (slow transit, normal transit, or pelvic floor dysfunction) underwent evaluation with transit marker study, cinedefecography, and anal physiology and were offered ileostomy as initial surgical management.

MAIN OUTCOME MEASURES

The primary measures were symptom improvement and self-reported quality of life improvement with increased patient satisfaction.

RESULTS

Eighty-seven patients underwent diverting loop ileostomy as initial surgical therapy. Group 1 had 54 (62%) patients who self-reported symptom improvement, discontinued anticonstipation medication, and had ileostomy output >200 mL/day. Of these 54 patients, 25 had colectomy with anastomosis, 16 (64%) of whom had symptom improvement, stayed off bowel medication, and had >1 bowel movement daily. Group 2 had 33 patients who did not meet the above criteria after initial ileostomy. Nine patients in group 2 elected colectomy with anastomosis after intensive counseling; 6 (66%) reported the same positive results above.

LIMITATIONS

The study limitations included: 1) no objective outcome measures of patient's perceived symptom improvement and satisfaction and 2) retrospective review.

CONCLUSION

Initial creation of diverting loop ileostomy may be offered to a subset of refractory constipation patients not falling into classical categories after thorough workup. Patients who self-report symptom improvement, have ileostomy output >200 mL/day, and do not require bowel medication may have acceptable results with subsequent colectomy and ileorectal anastomosis. See Video Abstract at http://links.lww.com/DCR/B854.

ILEOSTOMA EN ASA DERIVATIVA EN CASOS DE ESTREIMIENTO REFRACTARIOS AL TRATAMIENTO MDICO, QUE NO PERTENECEN A LAS CATEGORAS CLSICAS

ANTECEDENTES:El enfoque del estreñimiento refractario al tratamiento médico, que no siempre se presenta como las formas descritas clasicamente, es un desafío. Si bien el papel de la cirugía no está claro, se puede ofrecer una ileostomía en asa para medir la respuesta de los síntomas, seguida de colectomía en pacientes seleccionados.OBJETIVO:Evaluar los resultados de pacientes con estreñimiento, que no pertenecen a las formas clásicas de presentación, que se les realizó una ileostomía en asa de derivación, como intervención quirúrgica inicial. El objetivo secundario fue ofrecer a los pacientes una colectomía con anastomosis primaria y evaluar si mejoraban sus resultados después de la ileostomía.DISEÑO:El diseño del estudio fue una revisión retrospectiva.MARCO:Este estudio se realizó en el centro del piso pélvico de nuestro departamento de cirugía colorrectal, e incluyo los pacientes atendidos entre enero de 2006 y diciembre de 2018.PACIENTES:Se incluyeron los pacientes con estreñimiento refractario al tratamiento médico, derivados para evaluación quirúrgica, que no presentaban las formas clásicas de presentación (tránsito lento, tránsito normal, disfunción del suelo pélvico). Estos se sometieron a evaluación con estudio de tránsito colónico, cinedefecografía y fisiología anal, y se les ofreció una ileostomía en asa como tratamiento quirúrgico inicial.PRINCIPALES MEDIDAS DE RESULTADO:Las primeras medidas fueron la mejora de los síntomas y la calidad de vida informado por el paciente.RESULTADOS:Ochenta y siete pacientes fueron sometidos a ileostomía en asa como tratamiento quirúrgico inicial. El grupo 1 tenía 54 (62%) pacientes que informaron mejoría de los síntomas, interrumpieron la medicación proquinética y tuvieron un débito por la ileostomía >200 cc/día. De estos 54 pacientes, 25 se sometieron a colectomía más anastomosis primaria y 16 (64%) tuvieron una mejoría de los síntomas, dejaron de tomar medicamentos proquinéticos y tuvieron más de una evacuación al día. El grupo 2 tenía 33 pacientes que no cumplían con los criterios de mejoría de los síntomas después de la ileostomía inicial. Nueve pacientes del grupo 2 eligieron colectomía con anastomosis después de un asesoramiento intensivo, 6 (66%) informaron resultados positivos de mejoría de los síntomas.LIMITACIONES:Las limitaciones del estudio incluyeron 1) ninguna medida de resultado objetiva de la mejora y satisfacción de los síntomas percibidos por el paciente 2) revisión retrospectiva.CONCLUSIÓNES:La creación inicial de una ileostomía en asa de derivación se puede ofrecer a un subgrupo de pacientes con estreñimiento refractario que no entran en las categorías clásicas después de un estudio exhaustivo. La mejoría de los síntomas, informado por los pacientes, producción de ileostomía >200 cc/día y que no requieren medicación proquinética, pueden tener resultados aceptables con colectomía y anastomosis ileorrectal. Consulte Video Resumen en http://links.lww.com/DCR/Bxxx. (Traducción-Dr. Rodrigo Azolas).

Imaging and clinical assessment of functional defecatory disorders with emphasis on defecography

Functional defecation disorders (FDD) encompass causes of constipation associated with anorectal dysfunction, which include dyssynergia or inadequate defecatory propulsion. FDD are frequently encountered in clinical practice and may affect up to 33-50% of patients with chronic constipation. The etiology of FDD is unclear, however, it has been defined as an acquired, but subliminal behavioral disorder. Pathophysiologic mechanisms may include discoordination of rectoanal muscles, paradoxical contraction or insufficient relaxation of puborectalis and/or anal sphincter during defecation, and sluggish colonic transit. A combination of comprehensive clinical assessment, digital rectal examination and a battery of physiologic tests are needed to make an accurate diagnosis of FDD. Defecography may play a crucial role in the evaluation of FDD, especially when a balloon expulsion test (BET) and/or anorectal manometry (ARM) are equivocal or demonstrate contradictory results. In this review, we provide a thorough overview of the epidemiology, pathophysiology, diagnostic criteria, clinical and imaging evaluation, and treatment options for FDD, with an emphasis on available diagnostic imaging tools such as defecography and conventional fluoroscopic methods.

Animal models of cathartic colon

The incidence of cathartic colon has been increasing, but satisfactory treatments are still lacking. In order to study the pathological mechanisms of the disorder and identify effective treatment methods, researchers have established different animal models of cathartic colon. This minireview briefly summarizes several common cathartic colon animal models, induced with anthraquinone laxatives such as rhubarb, total anthraquinone, rhein, and emodin, or induced with diphenylmethane laxatives such as phenolphthalein. The advantages and limitations of these models are evaluated and analyzed. We hope that this review will facilitate the selection of suitable models and improve relevant modeling methods. We anticipate the development of more convenient and stable models that can reflect the characteristics of cathartic colon in humans, and serve as useful tools for further studies.

Prostaglandin E2 receptors and their role in gastrointestinal motility - Potential therapeutic targets

Prostaglandin E2 (PGE2) is found throughout the gastrointestinal tract in a diverse variety of functions and roles. The recent discovery of four PGE2 receptor subtypes in intestinal muscle layers as well as in the enteric plexus has led to much interest in the study of their roles in gut motility. Gut dysmotility has been implicated in functional disease processes including irritable bowel syndrome (IBS) and slow transit constipation, and lubiprostone, a PGE2 derivative, has recently been licensed to treat both conditions. The diversity of actions of PGE2 in the intestinal tract is attributed to its differing effects on its downstream receptor types, as well as their varied distribution in the gut, in both health and disease. This review aims to identify the role and distribution of PGE2 receptors in the intestinal tract, and aims to elucidate their distinct role in gut motor function, with a specific focus on functional intestinal pathologies.

The Enteric Nervous System and Its Emerging Role as a Therapeutic Target

The gastrointestinal (GI) tract is innervated by the enteric nervous system (ENS), an extensive neuronal network that traverses along its walls. Due to local reflex circuits, the ENS is capable of functioning with and without input from the central nervous system. The functions of the ENS range from the propulsion of food to nutrient handling, blood flow regulation, and immunological defense. Records of it first being studied emerged in the early 19th century when the submucosal and myenteric plexuses were discovered. This was followed by extensive research and further delineation of its development, anatomy, and function during the next two centuries. The morbidity and mortality associated with the underdevelopment, infection, or inflammation of the ENS highlight its importance and the need for us to completely understand its normal function. This review will provide a general overview of the ENS to date and connect specific GI diseases including short bowel syndrome with neuronal pathophysiology and current therapies. Exciting opportunities in which the ENS could be used as a therapeutic target for common GI diseases will also be highlighted, as the further unlocking of such mechanisms could open the door to more therapy-related advances and ultimately change our treatment approach.

Uncovering the Mechanisms of Chinese Herbal Medicine (MaZiRenWan) for Functional Constipation by Focused Network Pharmacology Approach

MaZiRenWan (MZRW, also known as Hemp Seed Pill) is a Chinese Herbal Medicine which has been demonstrated to safely and effectively alleviate functional constipation (FC) in a randomized, placebo-controlled clinical study with 120 subjects. However, the underlying pharmacological actions of MZRW for FC, are still largely unknown. We systematically analyzed the bioactive compounds of MZRW and mechanism-of-action biological targets through a novel approach called “focused network pharmacology.” Among the 97 compounds identified by UPLC-QTOF-MS/MS in MZRW extract, 34 were found in rat plasma, while 10 were found in rat feces. Hierarchical clustering analysis suggest that these compounds can be classified into component groups, in which compounds are highly similar to each other and most of them are from the same herb. Emodin, amygdalin, albiflorin, honokiol, and naringin were selected as representative compounds of corresponding component groups. All of them were shown to induce spontaneous contractions of rat colonic smooth muscle in vitro. Network analysis revealed that biological targets in acetylcholine-, estrogen-, prostaglandin-, cannabinoid-, and purine signaling pathways are able to explain the prokinetic effects of representative compounds and corresponding component groups. In conclusion, MZRW active components enhance colonic motility, possibly by acting on multiple targets and pathways.

Functional Disorders: Slow-Transit Constipation

Constipation is a very common complaint, with slow-transit constipation (STC) accounting for a significant proportion of cases. Old age, female gender, psychiatric illness, and history of sexual abuse are all associated with STC. The exact cause of STC remains elusive; however, multiple immune and cellular changes have been demonstrated. Diagnosis requires evidence of slowed colonic transit which may be achieved via numerous modalities. While a variety of medical therapies exist, these are often met with limited success and a minority of patients ultimately require operative intervention. When evaluating a patient with STC, it is important to determine the presence of concomitant obstructed defecation or other forms of enteric dysmotility, as this may affect treatment decisions. Although a variety of surgical procedures have been reported, subtotal colectomy with ileorectal anastomosis is the most commonly performed and well-studied procedure, with the best track record of success.

Effects of Low-frequency Current Sacral Dermatome Stimulation on Idiopathic Slow Transit Constipation

[Purpose] This study aimed to determine whether low-frequency current therapy can be used to reduce the symptoms of idiopathic slow transit constipation (ISTC). [Subjects] Fifteen patients (ten male and five female) with idiopathic slow transit constipation were enrolled in the present study. [Results] Bowel movements per day, bowel movements per week, and constipation assessment scale scores significantly improved after low-frequency current simulation of S2-S3. [Conclusion] Our results show that stimulation with low-frequency current of the sacral dermatomes may offer therapeutic benefits for a subject of patients with ISTC.

Consensus statement AIGO/SICCR diagnosis and treatment of chronic constipation and obstructed defecation (part II: treatment)

The second part of the Consensus Statement of the Italian Association of Hospital Gastroenterologists and Italian Society of Colo-Rectal Surgery reports on the treatment of chronic constipation and obstructed defecation. There is no evidence that increasing fluid intake and physical activity can relieve the symptoms of chronic constipation. Patients with normal-transit constipation should increase their fibre intake through their diet or with commercial fibre. Osmotic laxatives may be effective in patients who do not respond to fibre supplements. Stimulant laxatives should be reserved for patients who do not respond to osmotic laxatives. Controlled trials have shown that serotoninergic enterokinetic agents, such as prucalopride, and prosecretory agents, such as lubiprostone, are effective in the treatment of patients with chronic constipation. Surgery is sometimes necessary. Total colectomy with ileorectostomy may be considered in patients with slow-transit constipation and inertia coli who are resistant to medical therapy and who do not have defecatory disorders, generalised motility disorders or psychological disorders. Randomised controlled trials have established the efficacy of rehabilitative treatment in dys-synergic defecation. Many surgical procedures may be used to treat obstructed defecation in patients with acquired anatomical defects, but none is considered to be the gold standard. Surgery should be reserved for selected patients with an impaired quality of life. Obstructed defecation is often associated with pelvic organ prolapse. Surgery with the placement of prostheses is replacing fascial surgery in the treatment of pelvic organ prolapse, but the efficacy and safety of such procedures have not yet been established.

Role of SCF/c-Kit signaling pathway in the pathogenesis of cathartic colon

AIM: To investigate the role of SCF/c-Kit signaling pathway in the pathogenesis of cathartic colon.

METHODS: Thirty-six healthy adult SD rats were randomly divided into three groups (12 rats per group): control group, model group, and recovery group. The control group was given normal saline by gavage, and the model group and recovery group were given rhein suspension by gavage to induce cathartic colon. Specimens were taken immediately after modeling in the model group and 30 days after modeling in the recovery group. The intestinal transit function was assessed in each rats of each group by detecting the first melena discharge time. RT-PCR and Western blot were used to detect SCF/c-Kit mRNA and protein expression levels in colon tissue.

RESULTS: Compared to the control group, the first melena discharge time was significantly prolonged in the model group (491.5 ± 40.2 vs 373.4 ± 46.5, P < 0.01); however, there was no significant difference in the first melena discharge time between the model group and recovery group (477.9 ± 39.6 vs 491.5 ± 40.2, P > 0.05). Compared to the control group, c-Kit and SCF mRNA and protein expression levels were significantly decreased in both the model group and recovery group (all P < 0.01); however, there were no significant differences in c-Kit and SCF mRNA and protein expression levels between the model group and recovery group (both P > 0.05).

CONCLUSION: Reduced colonic motility in rats with cathartic colon may be associated with down-regulation of SCF/c-Kit signaling in colon tissue.

Evaluation of constipation

The evaluation of the chronically constipated patient is multifaceted and challenging. Many clinicians define constipation according to the latest Rome III diagnostic criteria for functional gastrointestinal disorders. Female sex, older age, low fiber diet, a sedentary life style, malnutrition, polypharmacy, and a lower socioeconomic status have all been identified as risk factors for functional constipation. In elderly patients, it is important to rule out a colonic malignancy as the cause of constipation. The initial evaluation of the constipated patient includes a detailed history to elicit symptoms distinguishing slow transit constipation from obstructive defecation. Slow transit and obstructive defecation are the two major subtypes of functional constipation. In addition, the clinician should identify any secondary causes of constipation. The office examination of the constipated patient includes an abdominal, perineal, and a rectal exam. Many patients improve with lifestyle modification. When dietary interventions and lifestyle modifications fail, many diagnostic studies are available to further evaluate the constipated patient. Sitzmark transit study, nuclear scintigraphic defecography, electromyography, anorectal manometry, balloon expulsion test, paradoxical puborectalis contraction, cinedefecography, and dynamic magnetic resonance imaging defecography have all been used to diagnose the underlying causes of functional constipation.

The role of peptide YY in gastrointestinal diseases and disorders (review)

Peptide YY (PYY) is affected in several gastrointestinal diseases and disorders. Changes in PYY appear to be an adaptive response to alterations in pathophysiological conditions caused by the disease. This applies to gastrointestinal diseases/disorders such as irritable bowel syndrome, inflammatory bowel disease, celiac disease, systemic sclerosis, and post-intestinal resection. By contrast, the changes in PYY in chronic idiopathic slow transit constipation (CST) seem to be of a primary nature, and may be one etiological factor of the disease. Abnormalities in PYY seem to contribute to the development of symptoms present in irritable bowel syndrome, inflammatory bowel disease, gastroenteropathy in long-standing diabetes and CST. The changes in PYY could, however, be favorable in some gastrointestinal disorders such as celiac disease, systemic sclerosis and post-intestinal resection state. Investigating changes in PYY in gastrointestinal diseases/disorders could be beneficial in clinical practice, where a receptor agonist or an antagonist can be used as a drug, depending on the condition. Similar to other neuroendocrine peptides/amines of the gut, PYY has broad physiological/pharmacological effects: it can bind to and activate several receptors with independent actions. Thus, in order to use PYY as a drug, receptor-specific agonists or antagonists need to be developed.

The use of Resolor (prucalopride) for chronic constipation in women

Chronic constipation is a common problem among women, is associated with anxiety and depression and can adversely affect quality of life (Mason et al, 2002). Chronic constipation is often unrelieved by simple laxatives, dietary manipulation or lifestyle modification, with other specialist treatment options being invasive and often not widely available. More recently attention has turned to newer prokinetic agents, such as prucalopride (Resolor®), which increase gut motility and intestinal transit, for the relief of chronic constipation. While these are not effective for everyone, there is evidence that prucalopride can increase bowel frequency, relieve bothersome symptoms associated with constipation and improve quality of life for women who have failed to achieve satisfactory relief from two other laxatives (National Institute for Health and Clinical Excellence).

Consensus statement AIGO/SICCR diagnosis and treatment of chronic constipation and obstructed defecation (Part II: Treatment)

The second part of the Consensus Statement of the Italian Association of Hospital Gastroenterologists and Italian Society of Colo-Rectal Surgery reports on the treatment of chronic constipation and obstructed defecation. There is no evidence that increasing fluid intake and physical activity can relieve the symptoms of chronic constipation. Patients with normal-transit constipation should increase their fibre intake through their diet or with commercial fibre. Osmotic laxatives may be effective in patients who do not respond to fibre supplements. Stimulant laxatives should be reserved for patients who do not respond to osmotic laxatives. Controlled trials have shown that serotoninergic enterokinetic agents, such as prucalopride, and prosecretory agents, such as lubiprostone, are effective in the treatment of patients with chronic constipation. Surgery is sometimes necessary. Total colectomy with ileorectostomy may be considered in patients with slow-transit constipation and inertia coli who are resistant to medical therapy and who do not have defecatory disorders, generalised motility disorders or psychological disorders. Randomised controlled trials have established the efficacy of rehabilitative treatment in dys-synergic defecation. Many surgical procedures may be used to treat obstructed defecation in patients with acquired anatomical defects, but none is considered to be the gold standard. Surgery should be reserved for selected patients with an impaired quality of life. Obstructed defecation is often associated with pelvic organ prolapse. Surgery with the placement of prostheses is replacing fascial surgery in the treatment of pelvic organ prolapse, but the efficacy and safety of such procedures have not yet been established.

Consensus statement AIGO/SICCR diagnosis and treatment of chronic constipation and obstructed defecation (part II: treatment)

The second part of the Consensus Statement of the Italian Association of Hospital Gastroenterologists and Italian Society of Colo-Rectal Surgery reports on the treatment of chronic constipation and obstructed defecation. There is no evidence that increasing fluid intake and physical activity can relieve the symptoms of chronic constipation. Patients with normal-transit constipation should increase their fibre intake through their diet or with commercial fibre. Osmotic laxatives may be effective in patients who do not respond to fibre supplements. Stimulant laxatives should be reserved for patients who do not respond to osmotic laxatives. Controlled trials have shown that serotoninergic enterokinetic agents, such as prucalopride, and prosecretory agents, such as lubiprostone, are effective in the treatment of patients with chronic constipation. Surgery is sometimes necessary. Total colectomy with ileorectostomy may be considered in patients with slow-transit constipation and inertia coli who are resistant to medical therapy and who do not have defecatory disorders, generalised motility disorders or psychological disorders. Randomised controlled trials have established the efficacy of rehabilitative treatment in dys-synergic defecation. Many surgical procedures may be used to treat obstructed defecation in patients with acquired anatomical defects, but none is considered to be the gold standard. Surgery should be reserved for selected patients with an impaired quality of life. Obstructed defecation is often associated with pelvic organ prolapse. Surgery with the placement of prostheses is replacing fascial surgery in the treatment of pelvic organ prolapse, but the efficacy and safety of such procedures have not yet been established.

Progress in understanding mechanisms underlying the regulatory effect of acupuncture on functional constipation

Functional constipation is a common and frequently-occurring disease whose etiology and pathogenesis are still not very clear. Experimental studies using animal models of cathartic colon have shown abnormalities in ultrastructural plexus of enteric nervous system (ENS), expression of multiple receptors, and interstitial cells of Cajal (ICC). Currently, there has been no consensus reached yet with regard to the mechanisms underlying the regulatory effect of acupuncture therapy on functional constipation, and the interaction among different regulatory mechanisms is not examined in depth. Future research should address this issue to better understand how acupuncture exerts therapeutic effects against functional constipation.

Slow-transit constipation with concurrent upper gastrointestinal dysmotility and its response to transcutaneous electrical stimulation

PURPOSE

Transcutaneous electrical stimulation (TES) speeds up colonic transit in children with slow-transit constipation (STC). This study examined if concurrent upper gastrointestinal dysmotility (UGD) affected response to TES.

METHODS

Radio-nuclear transit studies (NTS) were performed before and after TES treatment of STC as part of a larger randomised controlled trial. UGD was defined as delayed gastric emptying and/or slow small bowel transit. Improvement was defined as increase of ≥1 Geometric Centre (median radiotracer position at each time [small bowel = 1, toilet = 6]).

RESULTS

Forty-six subjects completed the trial, 34 had NTS after stimulation (21 M, 8-17 years, mean 11.3 years; symptoms >9 years). Active stimulation increased transit in >50% versus only 25% with sham (p = 0.04). Seventeen children also had UGD. In children with STC and either normal upper GI motility (NUGM) and UGD, NTS improved slightly after 1 month (57 vs. 60%; p = 0.9) and more after 2 months (88 vs. 40%; p = 0.07). However, mean transit rate significantly increased with NUGM, but not UGD (5.0 ± 0.2: 3.6 ± 0.6, p < 0.01).

CONCLUSION

Transcutaneous electrical stimulation was beneficial for STC, with response weakly associated with UGD. As measured by NTS, STC children with NUGM responded slightly more, but with significantly greater increased transit compared to those with UGD. Higher numbers are needed to determine if the difference is important.

The evaluation of constipation

Constipation is a major medical problem in the United States, affecting 2% to 28% of the population. Individual patients may have different conceptions of what constipation is, and the findings overlap with those in other functional gastrointestinal disorders. In 1999, an international panel of experts laid out specific criteria for the diagnosis of constipation known as the Rome II criteria. When patients present with complaints of constipation, a complete history and physical examination can elicit the cause of constipation. It is imperative to rule out a malignancy or other organic causes of the patient's symptoms prior to making the diagnosis of functional constipation. Many patients' symptoms can be relieved with lifestyle and dietary modification, both of which should be implemented before other potentially unnecessary tests are performed. Functional constipation is divided into two subtypes: slow transit constipation and obstructive defecation. Because many different terms are used interchangeably to describe these subtypes of constipation, physicians need to be comfortable with the language. Slow transit constipation is due to abnormal colonic motility. The diagnosis is made with the use of a colonic transit study. We continue to use a single-capsule technique as first described in the literature, but modifications of the capsule technique as well as scintigraphic techniques are validated and can be substituted in place of the capsule. Obstructive defecation is a much more complex problem, with etiologies ranging from rare diseases such as Hirschsprung's to physiologic abnormalities such as paradoxical puborectalis contraction. To fully evaluate the patient with obstructive defecation, anorectal manometry, defecography, and electromyography should be utilized. The different techniques available for each test are fully covered in this article. When evaluating each patient with constipation, it is important to keep in mind that the disease may be specific to one subtype or a combination of both subtypes. Because it is difficult to differentiate the subtypes from the patient's history, we feel it is imperative to evaluate patients fully for both slow transit and obstructive defecation prior to any surgical intervention. Furthermore, we have described many tests that need to be applied to one's population of patients on the basis of the capabilities and expertise the institution offers.

Slow transit constipation: a review of a colonic functional disorder

Constipation is a common gastrointestinal complaint that can cause significant physical and psychosocial problems. It has been categorized as slow transit constipation, normal transit constipation, and obstructed defecation. Both the definition and pathophysiology of constipation are unclear, but attempts to describe each of the three types have been made. Slow transit constipation, a functional colonic disorder represents approximately 15 to 30% of constipated patients. The theorized etiologies are disorders of the autonomic and enteric nervous system and/or a dysfunctional neuroendocrine system. Slow transit constipation can be diagnosed with a complete history, physical exam, and a battery of specific diagnostic studies. Once the diagnosis is affirmed and medical management has failed, there are several treatment options. Biofeedback, sacral nerve stimulation, segmental colectomy, and subtotal colectomy with various anastomoses have all been used. Of those treatment options, a subtotal colectomy with ileorectal anastomosis is the most efficacious with the data to support its use.

Short-term effects of magnetic sacral dermatome stimulation for idiopathic slow transit constipation: sham-controlled, cross-over pilot study

BACKGROUND AND AIM

An increase in recto-sigmoid colon activity through electrical stimulation of the sacral dermatomes has previously been reported. It has not been evaluated whether or not sacral dermatome stimulation has beneficial effects on constipation symptoms and anorectal function in constipated patients. Our aim was to evaluate short-term effects of magnetic stimulation of the sacral dermatomes on constipation symptoms and anorectal function in patients with idiopathic slow transit constipation.

METHOD

Fourteen patients with idiopathic slow transit constipation were enrolled. Constipation symptoms, stool form and anorectal function were assessed before treatment, and at 3 and 6 weeks of treatment. Six-week treatment consisted of either a 3-week period of sham treatment or a 3-week period of magnetic stimulation of the S2-S3 dermatomes, which was performed in a randomized cross-over design.

RESULTS

During the stimulation period, the frequency score of spontaneous bowel movements decreased in eight of the 14 patients (2.9 [2-3]vs 1.4 [0-2]), whose threshold volumes for urge to defecate and maximum tolerable volumes were significantly greater than those of the non-responders, and significantly decreased at the end of treatment. The degree of straining on defecation also significantly decreased in the responders. Responders had shorter right colonic transit time and longer left colonic transit time compared to the non-responders. Sham treatment did not affect constipation symptoms, stool form and rectal sensation.

CONCLUSION

Sacral dermatome stimulation may offer potential for therapeutic benefit for a subset of patients with idiopathic slow transit constipation, particularly constipated patients with rectal hyposensation or hindgut dysfunction.

[Obstructed defecation]

Adequate therapy of obstructed defecation (pelvic outlet obstruction) is often challenging, as the etiology and clinical symptoms include a wide range of disorders. Standardized diagnostic assessment has to differentiate between obstructed defecation caused by either pelvic outlet obstruction or slow transit constipation. Additionally, morphologic changes of colon, rectum, or the pelvic floor have to be separated from functional disorders. Providing defecography or dynamic MR of the pelvic floor, common causes of outlet obstruction such as sigmoidoceles, in which surgery is indicated, and rectal prolapse can be diagnosed with high accuracy. However, the diagnosis and therapeutic options in symptomatic rectocele and intussusception are controversial. Patients with functional disorders such as rectoanal dyssynergia are candidates for conservative treatment (biofeedback). To identify patients who will benefit from surgery for obstructed defecation, careful patient selection remains the crucial issue in diagnostic assessment.

Autonomic dysfunction may be an under-recognized cause of female fertility disorders

Female conditions of impaired fertility comprise a heterogeneous group of disorders that are attributed to various anatomic, hormonal and immunologic disturbances. We hypothesize that autonomic dysfunction may be a previously unrecognized factor in female fertility disorders. Emerging physiologic and molecular evidence suggests that autonomic balance varies during normal menstrual cycles with a shift to sympathetic bias during the luteal phase. Furthermore, many diseases associated with autonomic dysfunction show catamenial variations in patterns consistent with a shift to sympathetic bias occurs during the second half of normal menstrual cycles. The shift to sympathetic bias during the normal luteal phase may be an evolutionary adaptation to address the immunologic and physiologic demands for successful implantation and gestation. Through direct modulation of the lymphoid system and activation of the cortisol pathway, sympathetic bias promotes a shift to relative T helper (Th)-2 biased immunity which may favor maternal tolerance of the embryo by attenuating Th-1 mediated interference of implantation. Indeed, a growing body of evidence has implicated abnormal Th balance in fertility disorders, but the link has been attributed to factors other than autonomic function, such as hormonal factors. After implantation, maternal sympathetic bias may further support gestation through physiologic changes necessary to maintain placental perfusion pressure. We propose that insufficient shift to sympathetic bias during the luteal phase, which manifests in inadequate shift towards Th-2 bias and down-regulation of Th-1 function, may be the mechanism of impaired fertility in certain patients. Our hypothesis portends new potential methods to treat fertility disorders by modulating autonomic balance.

Effects of dachengqitang and acupuncture on human gastrointestinal motility disorder

AIM: To study the effects of dachengqitang and acupuncture at zusanli and neiting on disorders of the gastrointestinal motility and to elucidate the mechanism.

METHODS: The patients after abdominal surgery (n = 34), diabetes mellitus with gastroparesis (n = 29) and habitual constipation (n = 27) were selected to study the effects of dachengqitang and acupuncture of zusanli and neiting on disorder of the gastrointestinal motility with gastroduo-denojejunal manometry, electrogastrography (EGG), radio-immunity measurement of motilin, orocecal transit time test and ^99mTc-labeled scintigraphic gastric emptying.

RESULTS: Dachengqitang was able to obviously correct gastric electric dysrhythmia and increased the contractical period and contractical power of migrating motor complex(MMC) phase III, prevent gastroparesis, increased the motilin content in serum and improved postoperative motility dysfunction of gastrointestine. Dachengqitang could shorten orocecal transit time and improve the motility of gastrointestine in patients with diabetes mellitus and habitual constipation; acupuncture on the points of zusanli and neiting could improve rhythm of gastria in patients with dyspepsia, and improve the power of EGG and the gastric emptying.

CONCLUSION: Dachengqitang can improve recovery of the gastrointestinal motility in patients after abdominal surgery and treat patients of diabetes mellitus with gastroparesis and habitual constipation. Acupuncture of zusanli and neiting has the advantages of using easy and reliable curative effect and can be used in the treatment of the disorders of gastrointestinal motility.

Menstrual variation of autonomic balance may be a factor in exacerbations of certain diseases during the menstrual cycle

Exacerbation of certain medical conditions during specific phases of the menstrual cycle has long been recognized. Mechanisms of the cyclic variations are poorly understood, but are often attributed to fluctuations in reproductive hormones. We hypothesize that normal variations in autonomic balance during the menstrual cycle, which likely evolved as adaptations for reproduction, may contribute to catamenial variations in diseases independent of hormonal variations. Emerging evidence suggests that autonomic balance shifts towards sympathetic bias during the second half of the menstrual cycle. This shift can be seen as an evolutionary adaptation to address the immunologic and physiologic demands for successful implantation and gestation. Through direct modulation of lymphoid system and activation of the cortisol pathway, sympathetic bias promotes a shift to relative T helper (Th)-2-biased immunity which may favor maternal tolerance of the embryo by attenuating Th-1-mediated interference of implantation. Immune variance during the menstrual cycle has been implicated in menstrual fluctuations of many diseases, but until now the immune variance has been attributed to female hormonal changes. We propose that shifts in autonomic balance independently contribute to fluctuations in diseases by modulating the immune system. Still further, we propose that many other diseases fluctuate due to the direct nervous system actions of shifts in autonomic balance. Our hypothesis portends new therapeutic paradigms based on cyclical modulation of autonomic balance to address catamenial variations of medical conditions.