Study of Types of Pathophysiologic Patterns of Chronic Constipation and Its Correlation With Clinical Features

Towards Improving Diagnosis of Dyssynergic Defecation: A Small Step or a New Paradigm?

Introduction: Idiopathic chronic constipation is a common medical problem, with an average reported prevalence of 15% in North America. The prevalence of constipation is higher in women. Normal transit constipation, colonic inertia, and dyssynergic defecation (DD) are subtypes of idiopathic chronic constipation. There is limited agreement among tests to diagnose dyssynergic defecation. Dyssynergic defecatory symptoms, failure to expel a 60-mL balloon during a balloon expulsion test, and anal sphincter dyssynergic pattern on manometry testing are frequently used for diagnosing pelvic floor dyssynergia. The aim of this study is to compare the result of different studies in predicting DD. Methods: From January 2013 to May 2014, 143 consecutive constipated patients referred for pelvic floor testing were included in the study and the results of their work-ups were collected. Detailed questionnaires regarding patients’ defecatory symptoms, pertinent medical and surgical history, medication use, and digital rectal exam by gastroenterologists with motility expertise were collected prior to anorectal high-resolution manometry testing. Results: Our study includes 143 patients with constipation who were referred by their primary physician or gastroenterologist to our tertiary care center for pelvic floor testing. The mean age of the patients was 50 years with the majority of the patients being female (87%). Mean resting pressures were 62±6 mm Hg, mean squeeze pressures 143±13 mm Hg, and maximum tolerated volume was 201±63 mL; 111 patients (78%) had symptoms on questionnaire suggestive of DD. While 80 patients (56%) had an expert-performed digital rectal exam suggestive of DD, high-resolution manometry diagnosed dyssynergic pattern in 83 patients (58%). Expert-performed digital rectal exam is 87% sensitive and 85% specific for diagnosing DD versus dyssynergia documented by high-resolution manometry as the gold standard. Balloon expulsion test was abnormal (more than 2 minutes) in 57 subjects (40%). Among 32 patients with DD on manometry test who had normal balloon expulsion test (<2 min), 14 (43%) patients had resting anal pressure less than 45 mm Hg. Conclusion: Defecation is a complex process, influenced by stool consistency and pelvic floor neuromuscular sensation and function. While, there is no single criterion in diagnosing dyssynergic defecation (DD), the ability to expel a 60-mL balloon does not exclude the presence of pelvic floor dyssynergia. Therefore, a careful interpretation of the test results is important in making the correct diagnosis.

Introduction: Determine the efficacy of digital rectal examination (DRE) to identify patients with dyssynergic defecation (DD) by anorectal manometry (ARM) and balloon expulsion test (BET). Methods: We performed a prospective cohort study in adults with chronic constipation (CC) referred for ARM and BET from 5/11 to 5/14. All patients (pts) met the Rome III criteria for functional constipation. Each pt underwent a DRE by an experienced gastroenterologist and ARM/BET by 1 skilled technician. Data from DRE and ARM were collected using a standardized form using prespecified normal and abnormal criteria. During DRE, examiners assessed for sphincter relaxation or paradoxical contraction during simulated defecation. DRE results were compared to ARM (sphincter relaxation or contraction during simulated defecation) and BET (abnormal defined as the inability to pass a 50 ml water filled rectal balloon in <60 seconds). Positive predictive values (PPV = TP/TP+FP), negative predictive values (NPV=TN/TN+FN) and 95% confidence intervals were calculated for the overall group and each GI provider. Results: 209 (188 [90%] females, 86% Caucasian, Mean age = 48, and Mean BMI = 27.4) adults with CC who underwent DRE and ARM/BET were included in the analysis. Overall, 33% of patients who underwent ARM had a paradoxical sphincter contraction and 67% had a normal sphincter relaxation during simulated defecation. 28.9% had an abnormal BET. Compared to ARM, DRE correctly identified paradoxical sphincter contraction during simulated defecation in 34% of patients. Using ARM as a gold standard, DRE accurately detected normal anal sphincter relaxation during simulated defecation in 67% of patients. Predictive values for DRE using BET as a gold standard were similar. (Table 1). When data was stratified by the 3 providers, no significant differences were found in their ability to detect paradoxical sphincter contraction or normal sphincter relaxation during simulated defecation.Table 1Conclusion: These results suggest that the greatest benefit of DRE is derived from a normal examination. Because clinicians had difficulty accurately identifying paradoxical sphincter contraction during simulated defecation, patients with an abnormal DRE should be referred for anorectal manometry to assess for dyssynergic defecation. These results were generalizable amongst multiple providers at our institution. Disclosure - William D. Chey - Consultant: Astra-Zeneca, Forest, Ironwood, Perrigo, Prometheus, Nestle, Sucampo, Takeda, Furiex, SK, Ferring, Entera, Research Grant: Ironwood, Prometheus, Nestle, Perrigo. Jason Baker - no conflicts to disclose. Stacy Menees - no conflicts to disclose. Shanti Eswaran - no conflicts to disclose. Monthira Maneerattanaporn - no conflicts to disclose. Richard Saad - no conflicts to disclose.

INTRODUCTION: Chronic constipation (CC) is a common gastrointestinal complaint in clinical practice. Anorectal Manometry (ARM), Balloon Expulsion Testing (BET), and Defecography (DEF) are used to evaluate for dyssynergic defecation (DD) in CC patients. Literature provides poor to moderate agreement between ARM, BET, and DEF. The current threshold for a normal BET is <60 seconds. This threshold, though widely adopted, has not been rigorously validated. Our aim was to determine if a shorter or longer expulsion time offers improved performance characteristics to the current cut off for an abnormal BET of <60-seconds. METHODS: A retrospective cross-sectional study was conducted on 4746 CC patients ≥18 years of age who were referred for AFT at a single tertiary-care center from July 2003 to February 2020. All CC patients underwent an ARM and BET with a sub-set completing an ARM, BET, and DEF (n = 726). Abnormal AFT were defined as the following: ARM = simulated defecation responses with ≤20% anal relaxation; BET = the inability to expel a 50 ml water-filled balloon in ≤60-seconds; DEF = paradoxical contraction, increase anorectal angle, and/or the inability to expel barium contrast. DD was defined as an abnormal ARM and DEF. Linear BET time marks were coded for an abnormal test every 30-seconds: 30–120 seconds. Sensitivity, specificity, positive predictive values (PPV), and negative predictive values (NPV) were calculated for each 30-second BET time point using an abnormal ARM, DEF, and DD as individual state variables. RESULTS: Demographics (N = 4746) were as follows: mean age 48.8 ± 16.4 years (18–93), mean BMI 27.5 ± 7.2, 81.8% female, and 85.3% Caucasian. The BET sensitivity and specificity were similar at 30, 60, 90, and 120 seconds for an abnormal ARM, DEF, and DD (Table 1). The PPV for identifying an abnormal ARM for BET using a threshold of 120 seconds (sec) = 79%, for BET 90 sec = 68.0%, BET 60 sec = 62.1%, and BET 30 sec = 47.7% (Table 1). The NPV for BET 120 sec = 27.9%, BET 90 sec = 44.6%, BET 60 sec = 50.9%, and BET 30 sec = 62.7% (Table 1). Similar profiles for PPV and NPV for abnormal DEF and DD relative to various BET time thresholds (Table 1). CONCLUSION: A BET threshold of <60 seconds offers the best combination of performance characteristics for dyssynergic defecation relative to a few different gold standards and should remain the standard for defining an abnormal BET.Table 1

Constipation may be primary or secondary. Pathophysiologic subtypes of primary constipation are dyssynergic defecation (DD), slow (STC), and normal transit constipation (NTC). Clinical subtypes are functional constipation (FC) and constipation predominant IBS (C-IBS). The objectives of this paper are to study the clinical profile, categorize and compare various subtypes of primary constipation, and to assess the success of biofeedback therapy (BFT) in a non-randomized, uncontrolled open-label study among patients with DD. Consecutive constipation patients (April 2011 to December 2012) were evaluated. Patients <18years and secondary constipation were excluded. FC and C-IBS were classified by Rome III module. All patients, after excluding secondary constipation, underwent anorectal manometry (ARM) with balloon expulsion test and colon transit study (CTS). Patients with DD were given BFT. Out of 128 patients, 23 %, 58 %, and 19% had secondary constipation, FC, and C-IBS, respectively. Ninety-nine patients had primary constipation. Among those with primary constipation mean age was 53.5 (21-86) years, (77% males). Forty-six, 15, and 40 had NTC, STC, and DD, respectively. Out of those with DD, 34 had paradoxical anal contraction and 6 had impaired rectal propulsion. FC and C-IBS were clinically and pathophysiologically similar except for abdominal pain. Patients with DD were more likely to have history of finger evacuation, straining, incomplete evacuation, sensation of anorectal obstruction than no DD. Sixty-nine percent of the patients with STC had ≤3 stools/week compared to 37% with NTC (p-value 0.018). Thirty out of 40 (75%) patients with DD underwent BFT but 20 completed ≥4 sessions. Seventy percent with ≥4 sessions had improved complete spontaneous bowel movements (CSBM). NTC was the most common subtype of primary constipation. Symptoms of finger evacuation, sensation of anorectal obstruction, incomplete evacuation, and straining were more prevalent in DD. ARM and CTS could easily identify patients with DD and STC.

Objective To analyze the consistency between constipated symptoms and the parameters of gastrointestinal transit time (GITT), anorectal manometry (ARM) in elderly patients with functional constipation. Methods Total 111 patients (54 males and 57 females) with an average age of (70.2±6.5) years, who met Rome Ⅲ criteria of functional constipation were enrolled from June 2010 to October 2012. After enrollment, patients took two-week diary, recording the spontaneous bowel movements per week, stool type of Bristol Stool Form, the frequency and severity of defecation straining, sensation of anorectal obstruction, manual maneuvers and sensation of incomplete evacuation. The GITT and ARM tests were performed, and the consistency between symptoms and test results were analyzed. Results Patients with symptoms of slow transit, defecation disorder and mixed symptoms were 19.8% (22/111), 16.2% (18/111) and 59.5% (66/111) respectively; and 4.5% (5/111) patients had scattered symptoms. Based on results of GITT, slow transit subtype, defecation disorder subtype and mixed subtype were 54.1% (59/109), 1.8% (2/109) and 29.4% (32/109) respectively; and 14.7% (16/109) patients were with normal transit time. ARM results showed that 38.0% (41/109) of patients had dyssynergic defecation. The percentage of slow transit in GITT test showed no significant difference between patients with slow transit symptoms and mixed symptoms[50.0% (11/22) vs. 57.9% (33/57) , χ2=0.401, P=0.527]. The consistency of predominant symptom with GITT subtype was low (к=-0.013). The percentage of dyssynergic defecation detected with ARM showed no significant difference between patients with defecation disorder-predominant symptom and with mixed symptom [23.1% (6/24) vs. 38.2% (21/55) , χ2=1.813, P=0.178]. The consistency of defecation disorder-predominant symptom with dyssynergic defecation in ARM was low (к=-0.019). Conclusion The mixed subtype symptoms are the most common presentations of elderly patients with functional constipation, and the consistency of predominant constipated symptoms with GITT, ARM test results is poor. Key words: Aged; Constipation; Gastrointestinal transit; Anorectal manometry

IntroductionDigital rectal examination (DRE) and balloon expulsion test (BET) are simple tests to diagnose dyssynergic defecation (DD).AimTo determine differences in symptoms and manometry findings in patients with abnormal BET and normal BET. The secondary objective was to ascertain the sensitivity and specificity of BET and DRE + BET for the diagnosis of DD in an Indian setting using ARM findings as the gold standard.Material and methodsRetrospective analysis of patients with chronic constipation referred for anorectal manometry (ARM) between December 2012 and March 2019. DD was diagnosed using ARM. Findings on BET and, in a subset of cases, on DRE + BET were compared with ARM findings. The data were analyzed for sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Agreement of BET and DRE + BET with ARM was calculated using Cohen’s κ coefficient. A p-value of < 0.05 was considered significant.ResultsA total of 1006 cases (734 males, 73%) formed the study cohort. Patients with abnormal BET more frequently reported digitation, bleeding per rectum, and straining (p < 0.00001). Moreover, they had a significantly higher median basal pressure compared to those with normal BET (80 vs. 67, p = 0.03). DD was significantly more common in those with abnormal BET. The sensitivity, specificity, PPV, and NPV of BET in detecting DD were 28.29%, 97.15%, 81.13%, and 75.78%, respectively. The percentage of agreement was 76.34%, and there was fair degree of correlation between the two tests. In a smaller subset of cases (166), DRE and BET findings were both available for analysis. We noted that the sensitivity, specificity, PPV, and NPV of combined DRE + BET were 57.63%, 88.79%, 73.91%, and 79.17%, respectively. The Cohen’s κ correlation coefficient was 0.49, suggesting moderate agreement.ConclusionsPatients with abnormal BET more frequently report digitation, straining, and bleeding per rectum, and have higher resting anal pressure. BET is a good screening test for DD in an Indian setting.

Functional defecation disorders (FDD) are a prevalent etiology of refractory constipation. The diagnosis of FDD requires specific physiology testing, including anorectal manometry (ARM) and balloon expulsion test (BET). The aims of our study were to evaluate whether the complaint of painful defecation added to the Rome III symptoms questionnaire could help to differentiate subtypes of refractory chronic constipation. One hundred and ninety-eight constipated patients (Rome III Criteria) who had failed a 30-day fiber/laxative trial were enrolled. Before entering the study (T0) the patients underwent a digital rectal examination, including the assessment of tenderness elicited by traction of the puborectalis muscles (DRE-tenderness). Patients reporting painful defecation (occurring at least once per week) were specifically assessed at T0. Thirty days after T0, the patients underwent: DRE with DRE-tenderness evaluation. ARM + BET. Barium defecography (when ARM and BET were discordant). Colonic transit time evaluation with radiopaque markers. Based on these tests, the patients were classified into five subgroups: dyssynergic defecation (DD), inadequate defecatory propulsion (IDP), isolated structural outlet obstruction (mostly large rectocele), isolated slow transit constipation, and normal transit constipation. The association between symptoms and diagnostic outcomes was assessed using multivariate analysis based on binary logistic regression. Eighty-one patients (40.9%) reported weekly episodes of painful defecation, while 86 patients (43.3%) reported DRE-tenderness. Ninety-six patients (48.5%) showed features of FDD: 70 DD and 26 IDP; 25 (12.6%) showed isolated structural outlet obstruction, and 23 (11.6%) showed isolated slow transit constipation. No predictors were found for IDP. The subjective complaint of painful defecation added to the Rome III criteria is critical to improve the identification of specific subtypes of refractory chronic constipation, thus improving care and potentially decreasing the need for physiology testing.

One and Done: Is Measurement of the Rectoanal Pressure Gradient Enough to Diagnose Defecatory Disorders and Guide the Management of Constipation?

INTRODUCTION: Functional defecation disorders are a common cause of chronic constipation and the diagnosis include an abnormality in two or more of the following tests: balloon expulsion test (BET), anorectal manometry (ARM) or uncoordinated defecation on electromyography. Additionally, there have been four types of anorectal manometry dyssynergy patterns identified. Rao et al have shown that digital rectal examination (DRE) performed by a single expert gastroenterologist can accurately detect patients with dyssynergia. We conducted a study evaluating whether DRE performed by gastroenterology specialists could predict the presence and type of dyssynergia in patients with chronic constipation. METHODS: Patients with chronic constipation as defined by Rome IV criteria were evaluated by GI specialty providers at a single tertiary care hospital. After performing a DRE, each provider documented a prediction regarding the type of dyssynergy pattern that would be identified on ARM as well as whether the patient would pass the balloon during BET. An abnormal BET was defined as failure to pass the balloon in less than 60 seconds. Patients subsequently underwent ARM and BET and results of predicted and measured values on ARM and BET were compared. RESULTS: 21 patients were referred to undergo ARM and BET. 19 patients met the inclusion criteria. 16 displayed a dyssynergy pattern on ARM. Of the 16 patients, 11 were also identified to have features of dyssynergia on DRE with a detection rate of 69% (Table 1). One patient was noted to have features of dyssynergia on DRE but had normal ARM. Two patients had normal DRE with normal ARM. 11 of the 16 patients with dyssynergia on ARM had abnormal BET. Of the 11 patients with abnormal BET, 7 were predicted to have abnormal BET based on DRE (64% detection rate). DRE predicted the correct type of dyssynergia (type 1-4) in 31% of patients (Table 2). CONCLUSION: Studies have shown that DRE can predict dyssynergia when performed by a single expert gastroenterologist with a detection rate of 73%. Our analysis suggests that DRE can be used to predict dyssynergia on ARM and outcomes of BET even when multiple providers perform the exam. However, DRE is not a good predictor of the type of dyssynergia. Further studies are needed to evaluate the differences in detection rates between types of dyssynergia classified by ARM, and to assess whether there is a difference in detection rates between trainees and attendings.

Defining the pathophysiology of chronic constipation is critical for planning management. After excluding organic diseases, physician should speculate whether the constipated patient has a defecatory disorder or not. Recently, American Gastroenterology Association suggested an updated algorithm in diagnosis of chronic constipation.1 The major change was anorectal manometry and a rectal balloon expulsion test as the initial step which should be considered even before conventional laxative trial especially in patients who are highly suspected as having a defecatory disorder. This change inevitably posed the measurement of colon transit time in the last step of the algorithm and assessment of colonic transit is not recommended as early study any more. What is the rationale of this change? The American Gastroenterology Association medical position statement provided two reasonable issues. First, because near half of patients with defecatory disorders show concomitant slow colonic transit, slow transit time cannot rule out the presence of defecatory disorders and omit anorectal studies. Defecatory disorders are treated with pelvic floor retraining behavioral therapy, namely biofeedback, even if slow colonic transit is concomitant. Second reason is that the administration of laxative is the main initial therapy regardless of colon transit if there is no evidence of defecatory disorders. Normal transit constipation and slow transit constipation are treated similarly. Then, what is the clinical impact of slow colonic transit? We select very exceptional case of refractory chronic constipation as a candidate of surgical treatment according to the colonic transit. Colectomy could be effective in medically refractory constipated patients with slow colonic transit if defecatory disorders are not concomitant. The overall satisfaction rate of surgery was about 86% in a systematic review involving 39 reports and 1423 patients.2 Confirming slow colonic transit and ruling out defecatory disorders are mandatory for the successful outcome. The present study by Park et al3 suggested that the gas volume scoring could be a practical method assessing colonic transit. Even though the authors cannot find a positive correlation of colon transit time and colon gas volume score, they demonstrated that the difference of gas volume existed between slow transit and normal transit, defined as 45 hours (mean value + 1 standard deviation). The difference of gas volume score was small, 5.66% vs 4.15%, and the sensitivity and specificity of the cut-off value to diagnose slow colon transit was disappointing. The failure of presenting valuable cut-off colon gas volume score to differentiate slow colon transit is a big drawback of this study, because there was only small mean difference of colon gas volume score between the groups and this small difference can be easily made by manual processing of gas volume scoring or by confusing small bowel gas as colon gas. Also the range of colon gas volume score largely overlaps each other. Therefore the present outcome has insufficient clinical impact to replace conventional method using radiopaque markers to assess colon transit time. But primary physicians can roughly discriminate slow transit constipation based on this tendency of colon gas on simple x-ray and colon transit. When primary physicians encounter a constipated patient with a relatively larger amount of colon gas on simple abdominal x-ray, they can suspect the patient may have slow colon transit. There are some practical methods to assess constipated patient and this include digital rectal exam and Bristol stool scale. We can consider additional anorectal tests in patients of abnormal digital rectal exam.4 Abnormal digital rectal exam by skillful examiner can practically suspect defecatory disorder. Also Bristol stool scale is a practical indicator of colon transit and this simple illustration can be useful in a clinical setting of discrepancy between the bowel frequency and stool hardness.5 Besides of this physical exam and simple illustration, simple abdominal radiography may give some additional information to primary physician.

Dyssynergic defecation (DD) is a common yet underdiagnosed subtype of chronic constipation, often refractory to conventional treatment. Anorectal manometry (ARM) is a valuable physiological tool for identifying neuromuscular abnormalities contributing to DD. This study aimed to assess the diagnostic accuracy of ARM in detecting DD among patients with chronic constipation. A prospective observational study was conducted at Dr. D. Y. Patil Medical College, Pune, between January 2023 and February 2025, involving 102 patients with chronic constipation unresponsive to laxatives and lifestyle changes. Patients underwent high-resolution ARM and balloon expulsion test (BET). Dyssynergic patterns were classified using Rao's criteria. Data were analyzed using SPSS v26.0. Among the participants (mean age 45.53 ± 13.3 years), 75.5% were diagnosed with DD via ARM. The most prevalent manometric subtype was Type IV (28.4%), followed by Type I (21.6%). ARM demonstrated high diagnostic accuracy with a sensitivity of 97.4%, specificity of 88.5%, and overall accuracy of 95.1% when compared with BET. ARM is a reliable diagnostic modality for evaluating functional defecatory disorders. Incorporating ARM into routine evaluation of chronic constipation, especially when empirical therapies fail, can significantly enhance diagnostic precision and guide targeted interventions such as biofeedback therapy.

Lubiprostone: Easing the Strain of Constipation?

Microbial overgrowth (MO) in the small intestine can cause gastrointestinal symptoms and may arise from stasis, such as dysmotility. Microtypes of MO include small intestinal bacterial overgrowth (SIBO) and intestinal methanogen overgrowth (IMO). Dyssynergic defecation (DD) is associated with constipation and slow colonic transit (STC). Our aim was to assess the relationship between DD and MO. We retrospectively identified patients who underwent both anorectal manometry (ARM) and balloon expulsion testing (BET) for DD, and MO testing using either small intestinal aspirate culture or breath testing. SIBO was analyzed using two culture thresholds: ≥ 105 CFU/mL and ≥ 103 CFU/mL. Chi-square tests compared positive vs. negative results. 436 patients underwent culture of SB aspirates. At the ≥ 105 CFU/mL threshold, 41.7% were diagnosed with SIBO, and 87.4% at ≥ 103 CFU/mL. At ≥ 105 CFU/mL, percent anal relaxation was significantly lower in SIBO-positive patients. SIBO patients were more likely to have reduced anal relaxation (p = 0.032), but no other ARM parameters or BET > 60 s. At ≥ 103 CFU/mL, a more negative recto-anal pressure differential (RAPD) was observed, along with a combination of RAPD < -45 mmHg and resting anal pressure > 90 mmHg. 637 patients underwent breath testing for MO, with 174 positive results, predominantly showing IMO (73%). In this group, BET was significantly longer, and anal relaxation was significantly lower. SIBO at ≥ 103 CFU/mL was more prevalent in DD than STC (85.5% vs. 64.7%, p = 0.002). IMO was more common in DD than STC (p = 0.021). DD may be a risk factor for MO, often with evidence of methanogenesis.

Digital Rectal Examination Is a Useful Tool for Identifying Patients With Dyssynergia