Comparison of clinical and anorectal manometric findings in patients with functional constipation and irritable bowel syndrome

Introduction: Constipation is the most common digestive problem encountered in adult life. It is the whole of organic or non-organic (functional) disorders that occur in the intestinal function of the patients. According to the literature, anorectal manometry has been accepted as a first-line diagnostic tool for functional defecation disorder. Anorectal manometry studies including functional constipation and IBS-C patients are insufficient in the literature. For this reason, we aim to contribute to the literature with this study by making comparative analyzes of anorectal manometry data in patients with functional constipation and IBS-C who applied to our clinic. Method: Our study included 28 patients with functional constipation without an organic disease and 28 patients with IBS-C. In patients with functional constipation and IBS-C, after the proctological examination was completed, a calibrated anorectal manometry catheter was inserted through the anal canal by applying lubricant and measurements were made. With anorectal manometry; resting anal canal pressure, squeezing anal canal pressure, endurance tightening time, first sensation for rectal hyposensitivity, first urgency, very urgency defecation and maximum tolerated volume, cough reflex, rectoanal inhibitory reflex, balloon expulsion test, post-strain relaxation pressure parameters, functional defecation, and defecation disorder type were evaluated one by one. Results: Of the patients in our study, 50% (28 patients) were diagnosed with functional constipation, 50% (28 patients) were diagnosed with IBS-C according to Rome IV criteria, and 22 of 56 patients were male and 34 were female. Weekly defecation frequency was found to be statistically significantly higher in the IBS-C arm. Patients in the IBS-C arm had a mean frequency of 6.04 bowel movements per week, while patients in the functional constipation arm had a mean bowel frequency of 2.14 (p=0.001). While 75% of functional constipation patients were female in our study, male patients were in the majority (53.6%) in the IBS-C group. There was a significant gender difference between the patient groups (p=0.029). Insufficient ejaculation was also found significantly more frequently in the functional constipation arm in our study (p=0.016). Excessive straining or straining was statistically significantly more frequent in the functional constipation arm than in the IBS-C arm (p=0.001). According to our data, a statistically significant difference was found in squeezing anal canal pressure between the IBS-C and functional constipation arms. While the mean squeezing anal canal pressure was 124.93 median 112 in the IBS-C arm, it was found to be lower, with a mean of 95.75 median 96 in the functional constipation arm (p=0.011). In our study, in the functional constipation arm, the patients with abnormal profuse compression volume and maximum tolerable volume were 35.7%, while it was found to be 10.7% in the IBS-C arm. Statistically significant difference was found between the two arms in the very compaction volume and the maximum tolerable volume (p=0.027). Conclusion: The similar and normal reporting of 90% or more colonoscopic examinations in patients with functional constipation and IBS-C has led to a search for new methods to differentiate the diseases. Anorectal manometry method will have a common usage area because it contains valuable data in terms of short examination time and functional constipation and IBS-C distinction. Despite the limited number of patients in our study, important data were obtained in the differentiation of functional constipation and IBS-C with anorectal manometry. Studies in the literature show serious regional differences. There is no standardization of volume and pressure values in anorectal manometry in the differentiation of functional constipation and IBS-C patients and in the detection of functional defecation disorder. The mean volume and pressure values revealed by regional studies will play an important role in the diagnosis. The data in our study is important because there are limited studies evaluating functional constipation and IBS-C patients with anorectal manometry in our region. Keywords: functional constipation, irritable bowel syndrome, anorectal manometry