Constipation is a common bowel disorder which is reported by 1% to 80%. It has a significant impact on quality of life and on health care costs. It is generally divided into 2 types: primary or functional constipation with functional impairment of the colon and anorectal structures and secondary constipation related to organic disease, systemic disease, or medications (1). 
Symptoms of functional constipation include hard, infrequent bowel movements, often accompanied by symptoms of bloating and abdominal pain. Long-term these symptoms, incorrect defecation posture, Valsalva maneuvers, intra-abdominal pressure changes, spinal stability or core muscles weakness may be affected spinal structure and functions (2). The changes of spinal structure and functions, including spinal posture, mobility and stability, may be negatively affected the constipation. Chase et al. reported that children with functional constipation had decreased trunk control and impaired sitting posture compared to healthy children (3).  There is a need for detailed studies examining the spinal structure and functions in constipation.
Thus, the aim of this study was to investigate of spinal structure and functions in individuals with chronic functional constipation.

This study was designed as a case-control research. This study included 72 individuals with (Constipation group, n=36) and without (Control group, n=36) chronic functional constipation. The constipation group consisted of volunteers diagnosed with functional constipation according to Rome IV criteria between 18 to 50 years of age. In addition, they had constipation symptoms for more than 6 months. The control group included healthy volunteers between 18 to 50 years of age who had no constipation and pelvic floor dysfunctions. Neurological disease, systemic diseases, connective tissue diseases, various accompanying colonic conditions (such as intestinal obstruction, peritonitis, intestinal perforation, peptic ulcer, gastrointestinal bleeding or acute inflammation of abdominal organs), a history of abdominal radiotherapy, a history of abdominal or spine surgery, malignancy and pregnancy were excluded from the study. 
Physical and clinical characteristics were questioned. Constipation severity with the Constipation Severity Scale (CSS), bowel function with a bowel diary and stool type with the Bristol Stool Scale were assessed. Spinal posture, mobility and stability parameters were evaluated for spinal structure and functions. Spinal posture and mobility in the standing position in the sagittal plane were evaluated with the Spine Mouse posture and mobility measurement device (IDIAG M360®, Fehraltorf, Switzerland), and thoracic, lumbar and sacral angle and mobility values were determined. Spinal stability was assessed with trunk muscle endurance tests and Sahrmann test (Figure 1).
G*Power (G*Power Ver. 3.0.10, Franz Faul, Universität Kiel, Germany) package program was used for sample size calculation. First of all, a pilot study was conducted with 10 participants with constipation and 10 participants without constipation. The effect size was calculated as 0.80 according to the trunk muscle flexor scores of the pilot study. It was calculated that a total of 72 women, with at least 36 in each group, had to be recruited to obtain 90% power with 0.80 effect size, 0.05 type I error, 0.20 type I error. 
The normal distribution of data was evaluated with Shapiro-Wilk test. Descriptive data were presented as mean±standard deviation, frequency (n) and percentage (%). In the comparison of numerical data in the groups, the Independent Samples t-test was used. In the comparison of categorical data, the Chi-square test was used. The IBM SPSS Statistics 21.0 program was used for the analysis. ‘p<0.05’ was determined as the statistical significance level.

Physical characteristics (Constipation group: age=20.81±2.12 years, body mass index=22.30±2.59 kg/m2; Control group: age=20.50±1.85 years, body mass index=21.31±2.63 kg/m2) of the groups were similar (p>0.05). The duration of constipation was 15.05±14.04 months, the average number of daily defecations was 1.38±0.74, and the stool consistency (according to the Bristol Stool Scale) was mostly Type 2 (86.1%) in the constipation group.
There was no difference between the sagittal thoracic, lumbar and sacral angles and mobility values of the groups (p>0.05) (Table 1). Trunk muscle flexor (p=<0.001), extensor (p=0.006), right side lateral flexor (p=0.001), left side lateral flexor muscle endurance test scores (p=<0.001) and Sahrman test score (p=0.030) were lower in the constipation group compared to the control group (Table 1).

In this study, spinal stability was found to be decreased in individuals with chronic functional constipation compared to those without constipation. Spinal posture and mobility of the groups did not change.

According to these results, it may be important to consider the assessment of spinal instability in individuals with chronic functional constipation and recommend spinal stabilization exercises in management of these individuals.

Drossman DA. The functional gastroin-testinal disorders and the Rome III pro-cess. Gastroenterology. 2006;130:1377– 1390.
Goldish GD, Quast JE, Blow JJ, Kuskowski MA. Postural effects on intra-abdominal pressure during Valsalva maneuver. Arch Phys Med Rehabil. 1994 Mar;75(3):324-7. doi: 10.1016/0003-9993(94)90037-x. PMID: 8129587.
Chase JW. Stillman BC. Gibb SM. Clarke MC. Robertson VJ. Catto-Smith AG. Hutson JM. Southwell BR. Trunk strength and mobility changes in children with slow transit constipation. J Gastroenterol Hepatol. 2009 Dec;24(12):1876-84.