RESUMO
BACKGROUND & AIMS: Diagnostic tests for defecatory disorders (DDs) asynchronously measure anorectal pressures and evacuation and show limited agreement; thus, abdominopelvic-rectoanal coordination in normal defecation and DDs is poorly characterized. We aimed to investigate anorectal pressures, anorectal and abdominal motion, and evacuation simultaneously in healthy and constipated women. METHODS: Abdominal wall and anorectal motion, anorectal pressures, and rectal evacuation were measured simultaneously with supine magnetic resonance defecography and anorectal manometry. Evacuators were defined as those who attained at least 25% rectal evacuation. Supervised (logistic regression and random forest algorithm) and unsupervised (k-means cluster) analyses identified abdominal and anorectal variables that predicted evacuation. RESULTS: We evaluated 28 healthy and 26 constipated women (evacuators comprised 19 healthy participants and 8 patients). Defecation was initiated by abdominal wall expansion that was coordinated with anorectal descent, increased rectal and anal pressure, and then anal relaxation and rectal evacuation. Compared with evacuators, nonevacuators had lower anal diameters during simulated defecation, rectal pressure, anorectal junction descent, and abdominopelvic-rectoanal coordination (P < .05). Unsupervised cluster analysis identified 3 clusters that were associated with evacuator status (P < .01), that is, 10 evacuators (83%), 16 evacuators (73%), and 1 evacuator (5%) in clusters 1, 2, and 3, respectively. Each cluster had distinct characteristics (eg, maximum abdominosacral distance, rectal pressure, anorectal junction descent, anal diameter) and correlates that were more (clusters 1-2) or less (cluster 3) conducive to evacuation. Cluster 2 had 16 evacuators (73%) and intermediate characteristics (eg, lower anal resting pressure and relaxation during evacuation; P < .05). CONCLUSIONS: Women with DDs and a modest proportion of healthy women had specific patterns of anorectal dysfunction, including inadequate rectal pressurization, anal relaxation, and abdominopelvic-rectoanal coordination. These observations may guide individualized therapy for DDs in the future.
Assuntos
Canal Anal , Reto , Constipação Intestinal/diagnóstico , Defecação , Feminino , Voluntários Saudáveis , Humanos , Manometria , Reto/diagnóstico por imagemRESUMO
BACKGROUND & AIMS: The contribution of the abdominal muscles to normal defecation and disturbances thereof in defecatory disorders (DDs) are unknown. METHODS: In 30 healthy and 60 constipated women with normal rectal balloon expulsion time (BET) (n = 26) or prolonged BET (ie, DD; n = 34), seated anorectal pressures (manometry) and thickness (ultrasound) of the external and internal oblique and transversus abdominis muscles were measured simultaneously at rest, during hollowing, squeeze, evacuation, and a Valsalva maneuver. RESULTS: Compared with healthy women with a normal BET, DD women had a lower rectal and greater anal pressure increase during evacuation (P ≤ .05), and more activation of the internal oblique and the transversus abdominis muscles during squeeze (P < .05). The change in transversus abdominis thickness during a Valsalva maneuver vs hollowing (rho = 0.5; P = .002) and separately vs evacuation (rho = 0.7; P < .0001) were correlated in DD but not in healthy women with a normal BET. A principal component (PC) analysis of anorectal pressures and muscle thicknesses during evacuation uncovered a PC (PC3) that was associated with a prolonged BET. Higher PC3 scores were associated with low rectal and high anal pressures at rest and during evacuation, thinner external oblique muscle, and thicker internal oblique muscle during evacuation. A greater PC3 score was associated with increased odds for DD vs health (odds ratio, 1.84; 95% CI, 1.05-3.23), and separately vs constipation with a normal BET (odds ratio, 3.64; 95% CI, 1.73-7.69). CONCLUSIONS: Taken together, these findings show 3, possibly inter-related, disturbances suggestive of dyscoordination in DD: aberrant activation of abdominal muscles during squeeze in DD, dyscoordination of the abdominal muscles during various tasks in constipated women, and abdomino-anal dyscoordination.
Assuntos
Canal Anal , Defecação , Ataxia , Constipação Intestinal , Feminino , Humanos , Manometria , RetoRESUMO
BACKGROUND & AIMS: Some patients with defecatory disorders (DD) have high anal pressures that may impede rectal evacuation. Alpha-1 adrenoreceptors mediate as much as 50% of anal resting pressure in humans. We performed a randomized, placebo-controlled study of the effects of alfuzosin, an alpha1-adrenergic receptor antagonist, on anal pressures alone in healthy women and also on bowel symptoms in women with DD. METHODS: In a double-blind study performed from March 2013 through March 2017, anal pressures were evaluated before and after 36 women with DD (constipation for at least 1 year) and 36 healthy women (controls) were randomly assigned (1:1) to groups given oral alfuzosin (2.5 mg immediate release) or placebo. Thereafter, patients were randomly assigned (1:1) to groups given oral alfuzosin (10 mg extended release) or placebo each day for 2 weeks. Participants kept daily diaries of bowel symptoms for 2 weeks before (baseline) and during administration of the test articles (treatment). Weekly questionnaires recorded the overall severity of constipation symptoms, bloating, abdominal pain, nausea, and vomiting; overall satisfaction with treatment of constipation was evaluated at weeks 2 and 4. The primary endpoint was the change in the number of spontaneous (SBMs) and complete SBMs (CSBMs) between the treatment and baseline periods. We evaluated relationships between stool form, passage, and complete evacuation. RESULTS: Alfuzosin reduced anal resting pressure by 32 ± 3 mm Hg versus 16 ± 3 mm Hg for placebo (P = .0001) and anal pressure during evacuation by 26 ± 3 mm Hg versus 16 ± 3 mm Hg for placebo, (P = .03). However, alfuzosin did not significantly increase the rectoanal gradient, SBMs or CSBMs compared with placebo. Both formulations of alfuzosin were well tolerated. Hard stools and the ease of passage during defecation accounted for 72% and 76% of the variance in the satisfaction after defecation, respectively, during baseline and treatment periods. CONCLUSIONS: In a randomized trial, alfuzosin reduced anal pressure at rest and during simulated evacuation in healthy and constipated women, compared with placebo, but did not improve bowel symptoms in constipated women. This could be because the drug does not improve stool form or dyssynergia, which also contribute to DD. ClinicalTrials.gov number, NCT 01834729.
Assuntos
Canal Anal/fisiopatologia , Constipação Intestinal/tratamento farmacológico , Defecação/fisiologia , Hábitos , Quinazolinas/uso terapêutico , Antagonistas de Receptores Adrenérgicos alfa 1/uso terapêutico , Adulto , Constipação Intestinal/fisiopatologia , Defecação/efeitos dos fármacos , Método Duplo-Cego , Feminino , Seguimentos , Humanos , Masculino , Manometria , Pessoa de Meia-Idade , Pressão , Estudos Retrospectivos , Resultado do TratamentoRESUMO
OBJECTIVES: Functional dyspepsia is predominantly attributed to gastric sensorimotor dysfunctions. The contribution of intestinal chemosensitivity to symptoms is not understood. We evaluated symptoms and plasma hormones during enteral nutrient infusion and the association with impaired glucose tolerance and quality-of-life (QOL) scores in patients with functional dyspepsia vs. healthy controls. METHODS: Enteral hormonal responses and symptoms were measured during isocaloric and isovolumic dextrose and lipid infusions into the duodenum in 30 patients with functional dyspepsia (n=27) or nausea and vomiting (n=3) and 35 healthy controls. Infusions were administered in randomized order over 120 min each, with a 120-min washout. Cholecystokinin, glucose-dependent insulinotropic peptide, glucagon-like peptide 1 (GLP1), and peptide YY were measured during infusions. RESULTS: Moderate or more severe symptoms during lipid (4 controls vs. 14 patients) and dextrose (1 control vs. 12 patients) infusions were more prevalent in patients than controls (P≤0.01), associated with higher dyspepsia symptom score (P=0.01), worse QOL (P=0.01), and greater plasma hormone concentrations (e.g., GLP1 during lipid infusion). Moderate or more severe symptoms during enteral infusion explained 18%, and depression score explained 21%, of interpatient variation in QOL. Eight patients had impaired glucose tolerance, associated with greater plasma GLP1 and peptide YY concentrations during dextrose and lipid infusions, respectively. CONCLUSIONS: Increased sensitivity to enteral dextrose and lipid infusions was associated with greater plasma enteral hormone concentrations, more severe daily symptoms, and worse QOL in functional dyspepsia. These observations are consistent with the hypothesis that enteral hormones mediate increased intestinal sensitivity to nutrients in functional dyspepsia.
Assuntos
Glicemia/metabolismo , Duodeno/metabolismo , Dispepsia/metabolismo , Nutrição Enteral , Intolerância à Glucose/metabolismo , Adulto , Peptídeo C/sangue , Estudos de Casos e Controles , Colecistocinina/sangue , Dispepsia/sangue , Feminino , Polipeptídeo Inibidor Gástrico/sangue , Grelina/sangue , Peptídeo 1 Semelhante ao Glucagon/sangue , Glucose , Intolerância à Glucose/sangue , Humanos , Lipídeos , Masculino , Peptídeo YY/sangue , Qualidade de Vida , Índice de Gravidade de DoençaRESUMO
BACKGROUND: Diarrhea and rectal urgency are risk factors for fecal incontinence (FI). The effectiveness of bowel modifiers for improving FI is unclear. METHODS: In this double-blind, parallel-group, randomized trial, women with urge FI were randomly assigned in a 1:1 ratio to a combination of oral clonidine (0.1 mg twice daily) with colesevelam (1875 mg twice daily) or two inert tablets for 4 weeks. The primary outcome was a ≥50% decrease in number of weekly FI episodes. KEY RESULTS: Fifty-six participants were randomly assigned to clonidine-colesevelam (n = 24) or placebo (n = 32); 51 (91%) completed 4 weeks of treatment. At baseline, participants had a mean (SD) of 7.5 (8.2) FI episodes weekly. The primary outcome was met for 13 of 24 participants (54%) treated with clonidine-colesevelam versus 17 of 32 (53%) treated with placebo (p = 0.85). The Bristol stool form score decreased significantly, reflecting more formed stools with clonidine-colesevelam treatment (mean [SD], 4.5 [1.5] to 3.2 [1.5]; p = 0.02) but not with placebo (4.2 [1.9] to 4.1 [1.9]; p = 0.47). The proportion of FI episodes for semiformed stools decreased significantly from a mean (SD) of 76% (8%) to 61% (10%) in the clonidine-colesevelam group (p = 0.007) but not the placebo group (61% [8%] to 67% [8%]; p = 0.76). However, these treatment effects did not differ significantly between groups. Overall, clonidine-colesevelam was well tolerated. CONCLUSIONS AND INFERENCES: Compared with placebo, clonidine-colesevelam did not significantly improve FI despite being associated with more formed stools and fewer FI episodes for semiformed stools.
Assuntos
Clonidina , Incontinência Fecal , Humanos , Feminino , Clonidina/uso terapêutico , Incontinência Fecal/tratamento farmacológico , Incontinência Fecal/complicações , Cloridrato de Colesevelam/uso terapêutico , Diarreia/etiologia , Intestinos , Método Duplo-CegoRESUMO
BACKGROUND: This study compared the effects of ondansetron and placebo in patients with diabetes mellitus and symptoms of dyspepsia (diabetic gastroenteropathy [DGE]). METHODS: We performed a randomized, double-blinded, placebo-controlled study of ondansetron tablets (8 mg) three times daily for 4 weeks in DGE patients. Symptoms were assessed with the Gastroparesis Cardinal Symptom Index daily diaries. Gastric emptying (GE) of solids (scintigraphy) and duodenal lipid infusions (300 kcal over 2 h) were each assessed twice, with placebo and ondansetron. Drug effects on GE, symptoms during the GE study and during lipid infusion, and daily symptoms were analyzed. KEY RESULTS: Of 41 patients, 37 completed both GE studies and one completed 1; 31 completed both lipid infusions and four only placebo; and all 35 randomized patients completed 4 weeks of treatment. Compared to placebo, ondansetron reduced the severity of fullness (p = 0.02) and belching (p = 0.049) during lipid infusion but did not affect GE T1/2. Both ondansetron and placebo improved daily symptoms versus the baseline period (p < 0.05), but the differences were not significant. In the analysis of covariance of daily symptoms during the treatment period, the interaction term between treatment and the acute effect of ondansetron on symptoms during lipid challenge was significant (p = .024). CONCLUSIONS & INFERENCES: Ondansetron significantly reduced fullness during enteral lipid infusion in patients with DGE. Overall, ondansetron did not improve daily symptoms versus placebo. But patients in whom ondansetron improved symptoms during enteral lipid challenge were perhaps more likely to experience symptom relief during daily treatment.
Assuntos
Esvaziamento Gástrico , Ondansetron , Humanos , Ondansetron/administração & dosagem , Ondansetron/uso terapêutico , Masculino , Feminino , Método Duplo-Cego , Esvaziamento Gástrico/efeitos dos fármacos , Pessoa de Meia-Idade , Adulto , Gastroparesia/tratamento farmacológico , Dispepsia/tratamento farmacológico , Idoso , Complicações do Diabetes/tratamento farmacológico , Lipídeos/sangue , Resultado do Tratamento , Antieméticos/administração & dosagem , Antieméticos/uso terapêuticoRESUMO
BACKGROUND: The optimal methods for measuring and analyzing anal resting and squeeze pressure with high-resolution manometry (HRM) are unclear. METHODS: Anal resting and squeeze pressures were measured with HRM in 90 healthy women, 35 women with defecatory disorders (DD), and 85 with fecal incontinence (FI). Pressures were analyzed with Manoview™ software and a customized approach. Resting pressures measured for 20, 60, and 300 s were compared. During the squeeze period, (3 maneuvers, 20 s each), the squeeze increment, which was averaged over 5, 10, 15, and 20 s, and squeeze duration were evaluated. RESULTS: Compared to healthy women, the anal resting pressure, squeeze pressure increment, and squeeze duration were lower in FI (p ≤ 0.04) but not in DD. The 20, 60, and 300 s resting pressures were strongly correlated (concordance correlation coefficients = 0.96-0.99) in healthy and DD women. The 5 s squeeze increment was the greatest; 10, 15, and 20 s values were progressively lower (p < 0.001). The squeeze pressure increment and duration differed (p < 0.01) among the three maneuvers in healthy and DD women but not in FI women. The upper 95th percentile limit for squeeze duration was 19.5 s in controls, 19.9 s in DD, and 19.3 s in FI. Adjusted for age, resting pressure, and squeeze duration, a greater squeeze increment was associated with a lower risk of FI versus health (OR, 0.96; 95% CI, 0.94-0.97). CONCLUSIONS: These findings suggest that anal resting and squeeze pressures can be accurately measured over 20 s. In most patients, one squeeze maneuver is probably sufficient.
Assuntos
Canal Anal , Incontinência Fecal , Incontinência Fecal/diagnóstico , Feminino , Humanos , Manometria/métodos , DescansoRESUMO
BACKGROUND: It is suggested that patients with defecation disorders (DD) strain excessively or do a Valsalva maneuver (VM) during evacuation, resulting in rectoanal discoordination, which hinders rectal evacuation. However, definitive data are lacking. METHODS: Rectoanal pressures during evacuation and a VM were measured with seated high-resolution manometry (HRM) in 64 healthy and 136 constipated women with a normal (84 women, C-normal) or prolonged (52 women, C-abnormal) balloon expulsion time (BET). The number of abnormal rectoanal parameters during evacuation and the joint distribution of pressures during evacuation and a VM were used to discriminate between controls and C-abnormal BET patients. KEY RESULTS: The peak anal pressure (5 s) during a VM accounted for 0%, 26%, and 49% of the variance in anal pressure during evacuation in healthy women, C-normal BET, and C-abnormal BET. The association between anal pressure during a VM and evacuation was stronger in C-abnormal BET than in healthy women and C-normal BET (p for interaction <0.001). Fifty-eight of 64 controls and 33 of 52 C-abnormal BET patients had no or one abnormal parameter during evacuation; hence, the probability of C-abnormal BET was 33/91 (36%). In patients with no or one abnormal parameter during evacuation, a logistic model based on anal pressures during evacuation and a VM discriminated between controls and patients with C-abnormal BET with a sensitivity and a specificity of 67% and 75%. CONCLUSIONS: Assessment of rectoanal pressures during evacuation and a VM uncovers rectaoanal discoordination and facilitates the diagnosis of DD in selected patients.
Assuntos
Defecação , Manobra de Valsalva , Canal Anal , Constipação Intestinal/diagnóstico , Feminino , Humanos , Manometria/métodos , RetoRESUMO
OBJECTIVES: Defecation requires relaxation of the internal and external anal sphincters. High anal resting pressure is associated with painful constipation, defecatory disorders, and increased healthcare utilization in constipated patients; the mechanisms are unclear. Perhaps patients with a high anal resting pressure have a less distensible canal, which impedes defecation. METHODS: In 50 of 64 participants (33 healthy and 17 constipated women), anal pressures and distensibility were measured, respectively, with manometry and balloon distention combined with magnetic resonance imaging; rectal balloon expulsion time (BET) was also studied. RESULTS: The BET (P = .006) was longer, and the mean (SD) rectoanal pressure gradient (-58[40] vs -34[26] mm Hg, P = .03) was more negative in constipated than healthy women; anal resting pressure was not different. During anal distention, the balloon expanded rapidly at an opening pressure of 49 (18) mm Hg, which was lower (P < .0001) than resting pressure (90 [25] mm Hg). The resting pressure was correlated with the opening pressure (r = 0.57, P < .0001) and inversely (r = -0.38, P = .007) with maximum volume but not with anal distensibility (volume-pressure slope). In healthy women, the difference (opening-resting pressure) was correlated with anal relaxation during evacuation (r = 0.35, P = .04). Anal distensibility and sensory thresholds were not different between constipated and healthy women. CONCLUSIONS: Among healthy and constipated women, a greater anal resting pressure is correlated with greater opening pressure and lower maximum volume during distention, and, hence, provides a surrogate marker of anal distensibility. The difference (opening-resting pressure), which reflects anal relaxation during distention, is correlated with anal relaxation during evacuation. Anal resting pressure and distensibility were comparable in healthy and constipated women.
Assuntos
Canal Anal/fisiopatologia , Constipação Intestinal/fisiopatologia , Imageamento por Ressonância Magnética/métodos , Manometria/métodos , Adulto , Feminino , Humanos , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Nutrient-mediated release of cholecystokinin and glucagon-like peptide-1 (GLP-1) regulates gastric emptying (GE) via duodenogastric feedback mechanisms; GLP-1 also regulates postprandial insulin secretion. Some patients with functional upper gastrointestinal symptoms have impaired glucose tolerance during enteral dextrose infusion. Our hypothesis was that variants in CCK, GLP-1, and TCF7L2 (transcription factor 7-like 2 locus), which is associated with greatest genetic risk for development of type 2 diabetes mellitus, are associated with GE and independently with glucose tolerance. Our aims were to evaluate the associations between these GE, glucose tolerance, and these single nucleotide polymorphisms (SNPs). METHODS: Genetic variants, scintigraphic GE of solids, plasma glucose, insulin, and GLP-1 during enteral dextrose infusion (75gm over 2 hours) were measured. GE and enteral dextrose infusion were, respectively, evaluated in 44 (27 controls and 17 patients with functional dyspepsia or nausea) and 42 (28 controls, 14 patients) participants; of these, 51 participants consented to assessment of SNPs. Four functional SNPs were studied: rs6923761 and rs1042044 at GLP-1 receptor, rs7903146 (TCF7L2), and rs1800857 (CCK receptor). KEY RESULTS: Gastric emptying was normal in 38, rapid in 4, and delayed in two participants; 38 had normal, and four had impaired glucose tolerance. The T allele at rs7903146 (TCF7L2) was non-significantly associated (P = .14) with faster GE. The associations between SNPs and demographic variables, GE thalf , glucose tolerance and plasma GLP1 levels were not significant. CONCLUSIONS & INFERENCES: There is a trend toward an association between faster GE and the diabetes-associated allele at rs7903146 in TCF7L2. However, these SNPs were not associated with plasma glucose or GLP1 concentrations during enteral dextrose infusion.
Assuntos
Esvaziamento Gástrico/genética , Peptídeo 1 Semelhante ao Glucagon/genética , Intolerância à Glucose/genética , Receptores da Colecistocinina/genética , Proteína 2 Semelhante ao Fator 7 de Transcrição/genética , Adulto , Feminino , Gastroenteropatias/genética , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo ÚnicoRESUMO
BACKGROUND: We compared the utility of existing and modified versions of high-resolution manometry for diagnosing defecatory disorders (DD). METHODS: In 64 healthy and 136 constipated women, we compared left lateral (LL) and seated manometry, and analyzed with existing (ManoView™) and new methods, for discriminating between constipated patients with normal and prolonged rectal balloon expulsion time (BET). In both positions, the rectoanal gradient (RAG) and, for the new analysis, the pressure topography pattern during evacuation were used to discriminate between constipated patients without and with DD. KEY RESULTS: The BET was prolonged, suggestive of a DD, in 52 patients (38%). During evacuation, rectoanal pressures and the RAG were greater in the seated than the LL position (P≤.001). The new analysis identified 4 rectoanal pressure patterns. In the seated position, the BET was associated with the pattern (P=.0001), being prolonged in, respectively, 45%, 15%, 53%, and 0% of patients with minimal change, anal relaxation, paradoxical contraction, and transmission. Within each pattern, the RAG was greater (ie, less negative, P<.0001) in patients with a normal than a prolonged BET. Compared to the ManoView™ RAG in the LL position, the integrated analysis (ie, pattern and new RAG) in the LL position (P<.01) and the seated ManoView™ gradient (P=.02) were more effective for discriminating between constipated patients without and with DD. CONCLUSIONS & INFERENCES: Anorectal HRM ideally should be performed in the more physiological seated position and analyzed by a two-tier approach, which incorporates the overall pattern followed by the rectoanal gradient. These findings reinforce the utility of manometry for diagnosing DD.
Assuntos
Canal Anal/fisiologia , Constipação Intestinal/diagnóstico , Constipação Intestinal/fisiopatologia , Defecação/fisiologia , Manometria/métodos , Reto/fisiologia , Adulto , Doença Crônica , Feminino , Humanos , Manometria/tendências , Pessoa de Meia-IdadeRESUMO
BACKGROUND: High-resolution manometry (HRM) is used to measure rectoanal pressures in defecatory disorders and fecal incontinence. This study sought to define normal values for rectoanal HRM, ascertain the effects of age and BMI on rectoanal pressures, and compare pressures in asymptomatic women with normal and prolonged balloon expulsion time (BET). METHODS: High-resolution manometry pressures and BET were measured in 163 asymptomatic healthy participants. Women (96) and men (47) with normal BET were used to estimate normal values and the effects of age/BMI on pressures using a Medtronic 4.2-mm-diameter rectoanal catheter. KEY RESULTS: Age is associated with lower resting pressure, higher rectal pressure during evacuation, and a higher rectoanal gradient during evacuation in women and men. In women, the BET is also inversely correlated with age while the BMI is correlated with a higher threshold volume for discomfort and a longer BET. The anal squeeze pressure increment, squeeze duration, and HPZ length are higher in men than women. The rectoanal gradient during evacuation is also lower (ie, more negative) in asymptomatic women with an abnormal than a normal BET. CONCLUSIONS & INFERENCES: These findings provide an expanded database of normal values for anorectal HRM in men and women. Age and sex affect anal resting and squeeze pressures, respectively; rectal pressure during evacuation is also higher in older people. Less than 15% of asymptomatic people have BET >60 seconds, which is associated with manometry features of impaired evacuation.
Assuntos
Canal Anal/fisiologia , Manometria/métodos , Distúrbios do Assoalho Pélvico/fisiopatologia , Reto/fisiologia , Adulto , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Valores de ReferênciaRESUMO
BACKGROUND: Our aim is to explain the lack of clarity in the ways in which anxiety and depression, which are common in defecatory disorders (DD), may contribute to the disorder. In this study, we evaluate the effects of mental stress and relaxation on anal pressures and the mechanisms thereof. METHODS: In 38 healthy women and 36 DD patients, rectoanal pressures were assessed at rest and during mental stressors (ie, word-color conflict [Stroop] and mental arithmetic tests) and mental relaxation, before and after randomization to placebo or the adrenergic α1 -antagonist alfuzosin. KEY RESULTS: During the baseline Stroop test, the anal pressure increased by 6 ± 13 mm Hg (mean ± SD, P = 0.004) in healthy women and 9 ± 10 mm Hg (P = 0.0001) in constipated women. During mental arithmetic, the anal pressure increased in healthy (4 ± 8 mm Hg, P = 0.002) and constipated women (5 ± 9 mm Hg, P = 0.004). After relaxation, anal pressure declined (P = 0.0004) by 3 ± 4 mm Hg in DD patients but not in controls. Alfuzosin reduced (P = 0.0001) anal resting pressure (by 31 ± 19 mm Hg) vs placebo (16 ± 18 mm Hg). However, during the postdrug Stroop test, anal pressure increased (P = 0.0001) in participants who received alfuzosin but not placebo. CONCLUSIONS & INFERENCES: In healthy controls and DD patients, mental stressors likely increased anal pressure by contracting the internal anal sphincter; relaxation reduced anal pressure in DD patients. Alfuzosin reduced anal resting pressure but did not block the Stroop-mediated contractile response, which suggests that this response is not entirely mediated by adrenergic α1 receptors.