Hypothesis / aims of study
Defaecatory disorders (DD) affect 20% of the women in the general population and the prevalence increases with the aging population (1). DD include symptoms of anal incontinence (AI), obstructive defaecation (ODS), and functional anal pain. Anatomical factors contributing to these symptoms include rectocoele, intussusception, rectal prolapse, and enterocoele which are diagnosed by a combination of thorough history, clinical examination, and investigations.
DP enables dynamic evaluation of anatomical and functional aspects of the anorectum and pelvic floor during rectal expulsion of barium contrast in the upright, physiological position for defaecation(2).
We report the prevalence of anatomical abnormalities on defecating proctogram (DP) in patients with DD and determine if socio-demographic and clinical characteristics can predict abnormal anatomical findings on DP.
Study design, materials and methods
This is a single-institution study of patients with DD who underwent DP in a tertiary colorectal pelvic floor unit between March 2013 and May 2019. Data was collected from a prospectively maintained electronic database for socio-demographics which included ethnicity, socio-economic status, age, and gender while clinical factors included presenting symptoms, parity, prior history of pelvic floor surgery and hysterectomy and were collected retrospectively from patient notes.
A total of eight ethnicities were recorded: White British, White other, Black British, Black Caribbean, Black other, Asian, Mixed and Others. Socioeconomic status was proxied by the English Indices of Deprivation Measure 2019 (IMD)(3) which is an official measure of relative deprivation in England. The IMD scale ranges from 1 to 10. Patients were classified by the IMD score and divided into quintiles (1-5), by combining adjacent decile groups. The lowest quintile represented the most deprived while the highest quintile represented the least deprived.
Presenting complaints recorded were obstructed defaecation syndrome (ODS) (4), anal incontinence(4), mixed (ODS and anal incontinence), rectal prolapse(5), vaginal prolapse symptoms with defaecacory disorders (symptoms of anal incontinence, ODS or both) where vaginal symptoms included a feeling of heaviness, pressure or a lump coming down in the vagina(6), others (rectal bleeding and anal pain).
Parity was recorded as nulliparous (no live birth), primiparous (one live birth), multiparous (more than one but less than five live births) and grand multiparous (five or more live births) (7). However, due to few patients in the grand multiparous group which could have impacted the analysis, patients from multiparous and grand multiparous were combined.
Anatomical abnormalities identified on DP were pathological rectocoele (>2cm), pathological intussusception (grade III- V), and enterocoele. Data was analyzed after excluding missing values where p-value <0.05 was considered significant.
Results
A total of 1323 patients with defecatory disorders underwent a defecating proctogram. The mean age of patients was 53 years +/- 15.
Incidence
Pathological rectocoele was present in 465 (35.1%), pathological intussusception in 437 (33%) and enterocoele in 186 (14%) patients. One abnormality was detected in 555 (42%), two abnormalities in 221 (16.7%) and all three abnormalities in 29 (2.3%) patients.
Socio-economic predictors of anatomical abnormalities detected on DP
Gender
Female gender was found to be associated with the presence of a pathological rectocoele(>2cm) and enterocoele on DP compared to male gender, p-value <0.001.
Age
Patients under 50 years were more likely to have a pathological rectocoele (223, 39%) present on DP while those over 50 years were more likely to have pathological intussusception (283, 37.7%) and enterocoele (120, 16%).
Ethnicity
Unfortunately, 596 (45%) patients did not have ethnicity recorded. We did not find any difference in the presence of a pathological rectocoele, intussusception or enterocoele amongst different ethnicities.
Socio-economic status
This was proxied by IMD. We did not find any difference in the presence of a rectocoele, intussusception or enterocoele amongst patients belonging to different socio-economic groups.
Table 1 shows socio-demographic risk factors associated with anatomical abnormalities on defaecating proctogram in patients with defecatory disorders.
Clinical predictors of anatomical abnormalities detected on DP
The main presenting complaints recorded were as follows: obstructed defaecation (609, 46.3%), anal incontinence (287, 21.8%), mixed (301, 22.9%), rectal prolapse (69, 5.2%), others(rectal bleeding and anal pain) (18, 1.4%) and vaginal prolapse symptoms with DD (32,2.4%).
ODS and vaginal prolapse symptoms with DD were found to be associated with the presence of a pathological rectocele on DP (p-value <0.001), while rectal prolapse and vaginal prolapse symptoms with DD were associated with the presence of a pathological intussusception on DP (p-value <0.001). We did not find any variability in the presenting symptoms in patients with or without an enterocoele on DP.
Parity
Parity was associated with the presence of a pathological rectocoele on DP but not with intussusception or an enterocoele p-value of 0.005. The proportion of pathological rectocele found on DP increased with an increase in parity, p-value = 0.018.
Feeling of a vaginal bulge
This was significantly associated with the presence of a pathological intussusception (51, 44%) on DP. However, symptoms of feeling a vaginal bulge were not associated with the presence of a pathological rectocoele or enterocoele.
Previous pelvic floor surgery
Previous pelvic floor surgery was associated with the presence of an enterocoele on DP, p-value 0.002.
Hysterectomy
Previous hysterectomy was associated with the presence of an enterocoele on DP, p-value 0.004.
Table 2 shows clinical risk factors associated with anatomical abnormalities on defaecating proctogram in patients with defecatory disorders
Interpretation of results
• Incomplete or under-reporting of ethnicity undermines the attempts to address health inequalities and improve access, experience and outcomes for ethnic minorities.
• Data on functional abnormalities detected on proctogram such as dyssynergy or incomplete emptying was not recorded for this study. This could have resulted in under-reporting anatomical abnormalities due to poor function hindering the expulsion of rectal paste.
• Risk factors for rectocele development include traumatic vaginal delivery (due to its impact on the perineum), straining on a background of weakened pelvic floor muscle and connective tissue due to advancing age and multiple child births in females.
• Enterocoele is a marker of pelvic floor weakness and is commonly seen in women post-hysterectomy or those going through menopause with advancing age.
• Intussusception may be caused due to chronic straining. It is known that constipation which increases with age is coupled with straining and thus in the long term may lead to intussusception in patients