Hemorrhoidectomy is associated with relief of patient's symptoms in the vast majority of cases yet a few patients 
continue to complain of any of their original symptoms or acquire new ones. The cause of remote post-hemorrhoidectomy dyschesia may be suggested clinically, e.g. anal stricture. Frequently, the cause is not clear. This study included 21 patients  (7 males and 14 females) with an average age of 38.8 (±10.3) years. They presented with dyschesia > 3 months after hemorrhoidectomy. Defecation was assessed by employing a new analytical system: the Hydraulic / Efficiency Analysis of Defecation or the “HEAD" system. Digitized video recordings and X-ray images of video-defecography were analyzed on basis of hydraulic concepts of flow in pipes to calculate head loss during defecation. Efficiency analysis assessed the process of defecatory morphoconversion by a factor, overall defecatory efficiency, ODE. Morphoconversion subfunction efficiency analysis revealed the underlying functional disorder. Accordingly, an objective diagnosis of the severity and cause of  dyschesia was possible. The underlying disorder could be identified in all cases. Organic lesions (anal strictures, fissures, rectoanal intussusception) were the cause in 10 patients with system decompensation in five of them. Defecatory dyssynergia was the cause in 11 patients with decompensation in six cases. Patient's judgment of the severity of dyschesia did not correlate with measured severity. Four forms of dyssynergia were identified: pelvic, pelvi-anal, pelvi-anorectal, and anal. The precise diagnosis of the cause of dyschesia allowed selection of the appropriate line of therapy in all cases.