Does the consistency of stools define a distinct patient cohort in young men presenting with severe lower urinary tract symptoms?

ABSTRACT

Introduction:

Constipation has long been recognized to be associated with lower urinary tract symptoms (LUTS). However, there is little clinical data on bowel symptoms in young men who present with LUTS. This study analyses the association of stool consistency with severe LUTS in young men.

Methods:

This study is a secondary analysis of SciCOM 3 study examining young men presenting with LUTS. Stool consistency was recorded by the Bristol Stool Chart and classified into hard stools (Class 1, 2), normal stools (Class 3, 4), and loose stools (Class 5–7). LUTS, sexual dysfunction, bladder pain, non-bladder myofascial pain, perception of problems related to the bladder, and general well-being were captured by questionnaires along with basic clinical data. The poorest score on every question of each questionnaire was categorized as “severe”.

Results:

Four hundred and forty-eight young men (18–40 years; median 30 years, interquartile range 25–35 years) were studied across 16 centers. Stool consistency was hard, normal, and loose in 105 (23.4%), 284 (63.4%), and 59 (13.2%), respectively. Constipation was not associated with severe LUTS. Loose stools showed an association with six of the 13 questions on the International Consultation on Incontinence Questionnaire for male LUTS. Erectile dysfunction, bladder and nonbladder pain, and general well-being were found to be associated with loose stools but not with constipation. On multinomial logistic regression analysis, recurrent urinary tract infection and low body mass index were associated with hard stools, while low maximum flow rate, severe erectile dysfunction, and severe myofascial pain were associated with loose stools.

Conclusions:

Loose stools are an important association in young men presenting with severe LUTS.

INTRODUCTION

Bowel and bladder symptoms potentially interact through several crosstalk mechanisms.[1] Recognition of such association has been noted to be important across different patient groups and can have implications for evaluation and treatment. Constipation has been recognized as an important association of lower urinary tract symptoms (LUTS).[2,3,4] This association has been noted in both the neurogenic and the non-neurogenic populations and in adults as well as in children.[1] The association of bowel symptoms with LUTS has been studied in the community dwelling older men.[5] However, there is little clinical data on young men who present with LUTS regarding the association between stool consistency and individual urinary symptoms, as well as other clinical features. Further, there is very little evidence concerning loose stools and LUTS.

This study is a secondary data analysis of the SciCOM 3 project of the Functional and Female Urology Section of the Urological Society of India that examined LUTS in young men, to determine whether stool consistency was associated with a distinct clinical cohort in young men presenting with severe LUTS.[6]

METHODS

The methodology and primary findings of SciCOM 3 have been published earlier.[6] Briefly, the clinical epidemiology of young men between the age of 18 and 40 years presenting with LUTS was recorded across 16 national centers using validated questionnaires in a cross-sectional study. Ethics committee approval was obtained (AHH-C-S-013/04-23). LUTS were captured by the International Consultation on Incontinence Male Lower Urinary Tract Symptoms Questionnaire (ICIQ-mLUTS).[7] The ICIQ-mLUTS symptoms were classed as “severe” if the patient marked the maximum symptom score of 4. Usual stool consistency over the last 1 month was recorded by the Bristol Stool Chart (BSC).[8] BSC has 7 different classes of stool consistency with a visual as well text description of each class. Constipation was defined as class 1 or 2, whereas loose stools were defined as class 5, 6, or 7. Class 3 and 4 were regarded as normal stool consistency.

Sexual function was captured using the Massachusetts Male Aging Study (MMAS) Single-question Self-report of Erectile Dysfunction,[9] premature ejaculation was by captured the Premature Ejaculation Profile,[10] and the bladder pain was captured by the Interstitial Cystitis Symptom Index (Question 4).[11] All non-bladder pain were recorded by a (non-validated) 10-point VAS score (classified as no significant pain, score 0–1; mild pain 2–4; moderate pain 5–7; and severe pain 8–10). Severity of problems related to the bladder were measured by the Patient Perception of Bladder Condition questionnaire.[12] Well-being was captured by the WHO-5 Well-being Scale.[13] A history of urinary tract infection (UTI), duration of symptoms, comorbidities, and body mass index (BMI) (WHO Classification) were also recorded. The poorest score on each questionnaire was categorized as “severe.” For the WHO Well-being Q1 Score, the two most severe responses were clubbed for analysis. Patients underwent uroflow and ultrasonography to record any hydronephrosis and to measure the postvoid residual urine.

The inclusion and exclusion criteria, sample size estimation, and statistical analyses have been described earlier.[6] Briefly, all men between the ages of 18 and 40 years were included after an informed consent. Patients with an alternate specific urological diagnosis, such as stricture or neurogenic lower urinary tract dysfunction, or those on catheters (indwelling or intermittent), were excluded. The target recruitment number was 422 based on the population prevalence of 50%, 95% confidence level, and ± 5% margin of error. Descriptive statistics were reported as median and interquartile range (IQR). Kruskall–Wallis test was used for comparisons with Dunn–Bonferroni intergroup testing with correction for multiple testing, as appropriate. Multinomial logistic regression analysis for finding hard stools and loose stools (as compared with those reporting normal stools) was performed using the variables with significant association on univariate testing. For examining the association of each individual symptom with stool consistency, Pearson’s Chi-square analysis was performed with Bonferroni correction for intergroup testing. All the analyses were performed with the available data, ignoring any missing data points in the calculations. Missing data were expected to be minimal in view of the digital tablet-based recording system that was used. P <0.05 (two sided) was regarded as significant. Analysis was performed by SPSS version 25.0.0 (IBM Corp, NY, United States, 2017). The authors confirm the availability of, and access to, all original data reported in this study.

RESULTS

Data from 448 men were recorded (median age 30 years, IQR: 25–35 years). Stool consistency was noted to be hard in 105 (23.4%), normal in 284 (63.4%), and loose in 59 (13.2%). Basic evaluation data are depicted in Table 1. Duration of symptoms was significantly longer and maximum flow rates were slower, in patients reporting loose stools. Diabetes, hypertension, and hydronephrosis were noted in 3.6%, 2.7%, and 5.9%, respectively, with no difference in the distribution based on stool consistency. A history of UTI was noted in 16.7% of the patients.

Table 1.

Clinical associations of stool category in young men (18–40 years) presenting with lower urinary tract symptoms

	Hard stools (H)	Normal stools (N)	Loose stools (L)	P
Stool category: Median (IQR)
Age years	29 (24–34)	31 (26–34)	30 (25–37)	0.089
BMI	22.3 (19.9–25.6)	24.1 (21.5–26.3)	23.2 (21.5–25.5)	0.035 (H versus N)
Serum creatinine	0.9 (0.8–1.1)	0.9 (0.8–1.1)	0.9 (0.8–1.1)	0.551
Duration of LUTS in months	7 (4–15)	6 (3–14)	12 (6–30)	0.008 (N versus L)
Residual urine ml	35 (25–50)	35 (25–45)	33 (13–70)	0.707
MFR (mL/s0	15.0 (11.0–17.8)	15.0 (11.0–17.0)	11.3 (8.0–15.0)	<0.001 (H versus L and N versus L)
Number (percentage of column frequency)
Diabetes	2 (1.9)	9 (3.2)	1 (1.7)	0.697
Hypertension	3 (2.9)	10 (3.5)	3 (5.1)	0.760
Hydronephrosis	6 (5.9)	19 (6.7)	1 (1.7)	0.336
History of UTI	30 (28.6)	35 (12.3)	10 (16.9)	0.001 (H versus N)

For continuous variables, Kruskall–Wallis test with Dunn-Bonferroni inter-group analysis and correction for multiple testing was used. For categorical variables, Pearson’s Chi-square analysis was used. For intergroup difference, Bonferroni correction for multiple testing was applied. All P values two-sided, P<0.05 significant. Stool consistency was recorded by the BSC and classified as hard (class 1 or 2), loose (class 5, 6, or 7), or normal (class 3 and 4). IQR=Interquartile range, UTI=Urinary tract infection, BMI=Body mass index, LUTS=Lower urinary tract symptoms, BSC=Bristol Stool Chart

The association of severe individual symptoms of the ICIQ-mLUTS with stool consistency is depicted in Table 2. Constipation was not associated with severe LUTS. Loose stools showed an association with six of the 13 questions.

Table 2.

Association of individual lower urinary tract symptoms as recorded by the International Consultation on Incontinence Questionnaire for male lower urinary tract symptoms with stool category recorded by the Bristol stool chart in young men presenting with lower urinary tract symptoms

Severe ICIQ mLUTS symptom*	Number (percentage of column frequency)			Column difference, P
	Hard stools (H)	Normal N	Loose stools L
2A. Is there a delay before you can start to urinate? (n=445)	5 (4.8)	20 (7.1)	7 (12.3)	0.207
3A. Do you have to strain to continue urinating? (n=446)	7 (6.7)	20 (7.1)	11 (18.6)	0.011 (L versus N)
4A. Reduced strength of your urinary stream (n=448)	8 (7.6)	20 (7.0)	12 (20.3)	0.004 (L versus N)
5A. Do you stop and start more than once while you urinate? (n=448)	3 (2.9)	17 (6.0)	10 (16.9)	0.002 (L versus N)
6A. Feel that bladder has not emptied properly after urination (n=446)	7 (6.8)	24 (8.5)	12 (22.0)	0.003 (L versus N)
7A. Do you have a sudden need to rush to the toilet to urinate? (n=448)	2 (1.9)	11 (3.9)	9 (15.3)	<0.001 (L versus N)
8A. Does urine leak before you can get to the toilet? (n=448)	1 (1.0)	2 (0.7)	2 (3.4)	0.199
9A. Does urine leak when you cough or sneeze? (n=447)	0	1 (0.4)	0	0.748
10A. Leak for no obvious reason (n=448)	0	1 (0.4)	1 (1.7)	0.273
11A. Do you leak urine when you are asleep? (n=446)	1 (1.0)	2 (0.7)	1 (1.7)	0.760
12A. Slight wetting of pants after you finish urinating (n=448)	0	1 (0.40)	2 (3.4)	0.210
13A. How often do you pass urine during the day (n=448)	7 (6.7)	31 (10.9)	10 (16.9)	0.122
14A. How many times do you get up to urinate at night (n=448)	12 (11.4)	34 (12.0)	15 (25.4)	0.018 (L versus N)

*Severe implied that the patient scored the symptom as ‘4’ (or the highest level), Pearson’s Chi-square analysis. Stool consistency was recorded by the BSC and classified as hard (class 1 or 2), loose (class 5, 6, or 7), or normal (class 3 and 4). P<0.05 significant, All P values two-sided, for intergroup difference, Bonferroni correction for multiple testing was applied. ICIQ-mLUTS=Incontinence Questionnaire for Male Lower Urinary Tract Symptoms, BSC=Bristol stool chart

The association of severe associated clinical problems in young men presenting with LUTS is depicted in Table 3. There was an association of erectile dysfunction, pain, both bladder and nonbladder, and general well-being, with loose stools but not with constipation.

Table 3.

Association of pain, sexual function, and quality of life with stool consistency in young men presenting with lower urinary tract symptoms

Severe associated symptom*	Number (percentage of column frequency)			Column difference, P
	Hard stools (H)	Normal (N)	Loose stools (L)
Bladder pain ICSI Q4 (n=438)	1 (1.0)	9 (3.3)	3 (5.3)	0.272
Nonbladder myofascial pain VAS (n=447)	1 (1.0)	7 (2.5)	7 (11.9)	<0.001 (L versus N)
Erectile dysfunction MMAS (n=448)	0	1 (0.4)	4 (6.8)	<0.001 (L versus N)
Premature ejaculation PEP Q1 (n=436)	3 (2.9)	6 (2.2)	4 (6.9)	0.158
PPBC (n=448)	11 (10.5)	31 (10.9)	11 (18.6)	0.219
WHO well-being Q1 (n=447)	7 (6.7)	11 (3.9)	11 (18.6)	<0.001 (L versus N)

*Most severe category of marking for the symptom. Stool consistency was recorded by the BSC and classified as hard (class 1 or 2), loose (class 5, 6, or 7), or normal (class 3 and 4). All P values two-sided. For WHO Well-being Q1 score, two most severe responses were clubbed, Pearson’s Chi-square analysis. For intergroup difference, Bonferroni correction for multiple testing was applied. PEP=Premature ejaculation profile, VAS=Visual Analog Scale, ICSI=Interstitial cystitis symptom index, PPBC=Patient perception of bladder condition, BSC=Bristol Stool Chart, MMAS Massachusetts Male Aging Study

On multinomial logistic regression analysis, only recurrent UTI and BMI were associated with hard stools. Odds ratio for a history of UTI was 2.69 (95% confidence interval [CI]: 1.48–4.88; P = 0.001) in those reporting constipation as compared with those having normal stool consistency. Each unit reduction in BMI was associated with increased odds of constipation by 1.08 (95% CI: 1.01–1.15; P = 0.022) as compared with those having normal stool consistency. For loose stools, maximum flow rate, severe erectile dysfunction, and severe myofascial pain showed an independent association. Each 1 mL/s reduction in MFR (maximum flow rate) was associated with increased odds of loose stools 1.08 times (95% CI: 1.02–1.14; P = 0.012) as compared with those having normal stool consistency. Severe erectile dysfunction increased the odds 13.70 times (95% CI: 1.10–166.67; P = 0.042), whereas severe nonbladder myofascial pain increased the odds 5.37 times (95% CI: 1.27–22.73; P = 0.022) as compared with those reporting normal stools.

DISCUSSION

The SciCOM 3 study is perhaps the first attempt to examine clinical associations in young men presenting with LUTS, and this secondary analysis presents the association of stool consistency with LUTS. The distribution of stool consistency in our study was different from that reported in older men presenting with LUTS. In a large but older population-based cohort, normal stool consistency was noted in 80.1%, constipation in 4.7%, and loose stools in 14.4% of men above the age of 40 years.[5] In contrast, constipation was more common in our patients with an overall higher proportion of abnormal stool consistency. Another study that examined stool consistency in the symptomatic (South) Indian population noted strikingly similar rates for hard (13.8%) and loose stools (22.7%).[14] This might suggest that the stool consistency in young men presenting with LUTS is no different than the general population. However, the age range of the other study included men between the ages of 18 and 80 years and did not provide age-stratified results. One might expect a lower prevalence of abnormal stool consistency in young men in the community settings.

This study noted significant associations of loose stools with severe individual symptoms of the ICIQ-mLUTS questionnaire. There were higher odds of finding four of the five voiding symptoms that constitute the questionnaire. Nocturia, but not daytime urinary frequency, was also associated with loose stools. The odds of finding severe urgency, the cardinal symptom for overactive bladder, were the highest among all the symptoms (odds ratio 4.47; 95% CI 1.76–11.34). An association between OAB and IBS has been described earlier.[15] OAB has also been shown to be strongly associated with chronic constipation, fecal incontinence, and combined constipation with fecal incontinence in adult men and women above the age of 40 years.[16] Undocumented so far, this study found similar associations between loose stools and urgency in young men. Loose stools were found to be associated with nocturia in older men (above 40 years) examined in the National Health and Nutrition Examination Survey Study.[5] However, this study additionally found an association with voiding symptoms and loose stools. In our study, the association with loose stools seemed generally stronger with voiding rather than storage LUTS.

Our study noted that patients with loose stools had increased odds of reporting a major impact on well-being as captured by the WHO-5 Well-Being Scale (Question 1). This key question examines whether an individual feels cheerful and in good spirits. The odds of finding a response of the two poorest scores on this six-point ordinal scale was 5.67 (95% CI: 2.33–13.80). In contrast, patients with constipation did not show such an association. Loose stools have been noted to be risk factors for fecal incontinence in men.[17] Fecal incontinence is also associated with urinary incontinence and impacts the quality of life.[18] While this study did not specifically captured fecal incontinence, such patients might logically be expected to mark their stool consistency as “loose,” given that this was a nonneurogenic, young male population. Fecal incontinence is not uncommon in the general population, with a large population-based study noting it in 8.3% of all the adults.[17] There is an age-associated increase in prevalence from 2.6% in the third decade to 15.3% beyond the seventh decade. In men, loose stools, poor self-rated health, and the presence of urinary incontinence have been noted to be risk factors for fecal incontinence.[17]

An association between bowel symptoms, urinary symptoms, and erectile dysfunction has previously been reported in men, but the study examined constipation and did not specifically report on young men.[19] Men with loose stools were far more likely to report erectile dysfunction in this study. Such an association was not noted with constipation, and stool consistency was not associated with premature ejaculation. Hard stools were associated with a history of UTI (28.6% vs. 12.3% and 16.9% in those with normal or loose stools, P = 0.001). Such an association has been documented in older men as well.[1,20]

Young men with LUTS manifest significant barriers in seeking health care. In a population-based study from Denmark, men between the ages of 20 and 39 years showed the highest barrier. A delay in seeking health care was noted in 73.4%–84.5% of men with voiding difficulty, urgency incontinence, daytime frequency, and nocturia. Young men were more likely to report being “too busy” or feeling embarrassed in seeking a consultation for their LUTS as compared with older men.[21] In our study, young men with LUTS having loose stools were more likely to report a long duration of symptoms (beyond 12 months). However, based on the overall findings, this might not necessarily reflect a delay in treatment-seeking behavior but might reflect a more severe, and perhaps more refractory form of presentation. The reasons for long duration of symptoms were not specifically sought in the protocol for SciCOM 3.

There are several possible mechanisms of association between stools and LUTS.[1] Such pelvic organ crosstalk can occur at four different levels: peripheral neural, spinal central, or supraspinal cross-sensitization, and non-neural mechanisms.[1] Gut microbiome has been noted to affect both bowel as well as lower urinary tract health and alterations have been shown to be associated with both LUTS and bowel symptoms.[22,23] Psychological morbidities can be associated with bowel symptoms, urinary symptoms, and abnormal sexual function.[24,25] Abnormal activity in the insula region of the brain has been noted in both overactive bladder and irritable bowel syndrome.[1] Constipation has an impact on the pelvic floor, which can in turn impact the lower urinary tract function. A distended rectum in close proximity to the bladder might also have a mechanical impact. Pelvic floor activity might be enhanced in individuals with habitual loose stools to avoid fecal soiling. Such enhanced activity might manifest as voiding dysfunction. Circulating immune mediators and inflammatory cytokines can impact both bladder and bowel and have been shown to be of possible relevance in patients with overactive bladder.[1] It is possible that one or more of these mechanisms might be responsible for the constellation of symptoms that are seen in young men with LUTS. Several of these mechanisms could potentially impact the development or perception of pain as well as sexual dysfunction.

There are important limitations to this analysis. Stool consistency was recorded by BSC without regard to any specific bowel diagnosis. Hence, it is not possible to conclude whether abnormal stool consistency was due to irritable bowel syndrome or other specific diagnoses. BSC scoring was done based on typical stool consistency over the last 1 month. While this is likely to exclude acute factors such as infective diarrhea or transient constipation, however, this cannot be confirmed. Stool consistency does not always give a true reflection of bowel symptoms. For instance, functional constipation can present as fecal incontinence.[26] The BSC is a simple, visually supported, single-response question. However, it does not capture fecal incontinence, although such patients might be expected to mark the stool consistency as “loose.” It also does not capture stool frequency. Given the large amount of information being collected in the SciCOM 3 study, a more detailed bowel analysis questionnaire, such as the ROME III Questionnaire was deemed unsuitable for the purpose. We have not studied the diet of these men. The diet of the Indian population generally has a smaller proportion of meat and animal protein, and there is a higher prevalence of vegetarianism.[27] This might have led to a lower propensity for hard stools in our study population.

CONCLUSIONS

Loose stools are an important association in young men presenting with severe LUTS and have not been previously reported in young men. It is important to seek a history of loose stools in young men presenting with LUTS since it might be a marker for a more severe presentation.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.