An evaluation of colorectal diseases: surgical aspects and new insights into the mechanisms of fecal continence

Colorectal diseases can be inborn or they can appear later in life and depending on the severity can be treated either conservatively or surgically. After treatment these patients may still suffer from symptoms relating to their disease, like fecal incontinence. To achieve a better understanding of the pathophysiology of fecal incontinence in these patients, understanding of the physiology of fecal continence is essential. Functioning of the voluntary contraction of the puborectal muscle is believed to be the foundation of fecal continence. In the first part of this thesis, we showed that also involuntary contractions can control fecal continence, which we called the puborectal continence reflex. We found that this reflex is not regulated by the pudendal nerve, one of the major nerves of the pelvic floor, and that this reflex is only activated in case of solid stool, not liquid. In the second part, we focus on the colorectal diseases. An example of inborn colorectal diseases are congenital anorectal malformations (CARM). We found that, in contrary to the male preponderance the literature describes, there is an equal sex distribution: the prevalence of CARM in girls is currently underestimated. Additionally, 17% of the CARM patients concomitantly suffer from congenital heart defects, even the mild forms. Furthermore, most patients with CARM possess continence reflexes, as we have described in the first part. In patients who underwent colorectal surgery with an ileal pouch anal anastomosis, a proximal, stapled, anastomosis with a three stage procedure results in better fecal continence outcomes.