+1 Recommend
0 collections
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Normative Values for Colonic Transit Time and Patient Assessment of Constipation in Adults With Functional Constipation: Systematic Review With Meta-Analysis

      Read this article at

          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.


          Availability of normative patient outcome data may assist in designing experiments and estimating sample sizes. The purpose of this review was to determine normative ranges for colonic transit time (CTT), Patient Assessment of Constipation-Symptoms (PAC-SYM), and Patient Assessment of Constipation-Quality of Life (PAC-QOL) in adults diagnosed with functional constipation per Rome III guidelines. Pooled estimates were derived from random-effects meta-analysis. Meta-regression was used to explore sources of heterogeneity among studies. A total of 24 studies (3786 patients) were included in the review. In 10 studies with 1119 patients, pooled CTT was 58 hours (95% confidence interval [CI]: 50-65 hours). Publication bias was not evident (Egger P = .51); heterogeneity was high ( I 2 = 92%, P < .001). In meta-regression, geographical location explained 57% of the between-study variance, with CTT significantly longer in studies conducted in Europe (71 hours) compared with Asia (49 hours) or the Americas (44 hours). In 9 studies with 2061 patients, pooled PAC-SYM was 1.70 (95% CI: 1.58-1.83). Publication bias was not evident (Egger P = .44). Heterogeneity was high ( I 2 = 90%, P < .001); however, no study or patient factor influenced PAC-SYM in meta-regression. In 12 studies with 1805 patients, pooled PAC-QOL was 1.97 (95% CI: 1.70-2.24). Publication bias was not evident (Egger P = .28); heterogeneity was high ( I 2 = 98%, P < .001). In meta-regression, age explained 52% of the between-study variance, with older age associated with lower PAC-QOL scores. Overall, in adults diagnosed with functional constipation per Rome III criteria, significant heterogeneity in CTT, PAC-SYM, and PAC-QOL exists among studies. Variability among studies may be explained by geography and patient factors.

          Related collections

          Most cited references 27

          • Record: found
          • Abstract: found
          • Article: not found

          Improved tests for a random effects meta-regression with a single covariate.

          The explanation of heterogeneity plays an important role in meta-analysis. The random effects meta-regression model allows the inclusion of trial-specific covariates which may explain a part of the heterogeneity. We examine the commonly used tests on the parameters in the random effects meta-regression with one covariate and propose some new test statistics based on an improved estimator of the variance of the parameter estimates. The approximation of the distribution of the newly proposed tests is based on some theoretical considerations. Moreover, the newly proposed tests can easily be extended to the case of more than one covariate. In a simulation study, we compare the tests with regard to their actual significance level and we consider the log relative risk as the parameter of interest. Our simulation study reflects the meta-analysis of the efficacy of a vaccine for the prevention of tuberculosis originally discussed in Berkey et al. The simulation study shows that the newly proposed tests are superior to the commonly used test in holding the nominal significance level. Copyright 2003 John Wiley & Sons, Ltd.
            • Record: found
            • Abstract: found
            • Article: not found

            Systematic review: impact of constipation on quality of life in adults and children.

             M Geraint,  D Candy,  J Belsey (2010)
            Comparison of quality of life (QoL) across disease areas requires the use of appropriate tools. Although many studies have investigated QoL in constipation, most used disease-specific tools that are inappropriate for cross-comparisons. To identify studies of QoL in constipation and to compare these results with other chronic conditions. A comprehensive literature search identified studies in constipation that used a generic QoL tool. Results were statistically pooled where possible and compared with published results using the same tools in other chronic conditions. A total of 13 qualifying studies were identified, 10 in adults and three in children. Results from eight studies using the SF-36/12 tools were pooled; the remaining five were narratively reported. Mental and physical components of QoL scores were consistently impaired in both adult and child populations, with the greatest impact being seen in secondary care studies. Mental health effects predominated over physical domains. The magnitude of impact was comparable with that seen in patients with allergies, musculoskeletal conditions and inflammatory bowel disease. The impact of constipation on QoL is significant and comparable with other common chronic conditions. Improving management may prove to be an effective way of improving QoL for a substantial number of patients.
              • Record: found
              • Abstract: found
              • Article: not found

              Simplified assessment of segmental colonic transit.

              Transit times of radiopaque markers through the human gut were measured by published techniques and compared with a simplified method. Three sets of distinctive markers were ingested by 24 healthy persons on 3 successive days. In the first part of the study, daily abdominal x-rays were taken and individual stools were collected for radiography. Mouth-to-anus transits were assessed from the fecal output of markers and mean colonic and segmental colonic transits were calculated from the daily radiographs. These established methods were then compared with estimates of total colonic and segmental transits based on a single abdominal film, taken on the fourth day. The single-film technique correlated well with values obtained from the previous, but more inconvenient, methods. Using the simpler approach, colonic transit was assessed in 49 additional healthy subjects, for a total group of 73. Total colonic transit was 35.0 +/- 2.1 h (mean +/- SE); segmental transits was 11.3 +/- 1.1 h for the right colon, 11.4 +/- 1.4 h for the left colon, and 12.4 +/- 1.1 h for the rectosigmoid. Men had significantly shorter transits for the whole colon than did women (p less than 0.05), and this difference was apparent to some extent in the right (p = 0.06) and left colon (p = 0.07) but not in the rectosigmoid. Age did not influence transit significantly nor did a small dose of supplemental fiber. The technique is simple, convenient for clinical usage, and reduces the exposure to radiation to acceptable levels. There should be a role for this approach in the evaluation of colonic transit in selected patients.

                Author and article information

                Clin Med Insights Gastroenterol
                Clin Med Insights Gastroenterol
                Clinical Medicine Insights. Gastroenterology
                SAGE Publications (Sage UK: London, England )
                31 August 2017
                : 11
                [1 ]Miller Scientific Consulting, Asheville, NC, USA
                [2 ]Global Health and Nutrition Sciences, DuPont Nutrition & Health, Kantvik, Finland
                Author notes
                Larry E Miller, Miller Scientific Consulting, 1854 Hendersonville Road #231, Asheville, NC 28803, USA. Email: larry@
                10.1177_1179552217729343 CMG-0042875
                © The Author(s) 2017

                This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License ( which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access page(

                Custom metadata
                January-December 2017


                Comment on this article