Functional Megacolon in Children (Etiology, Pathogenesis, Diagnosis): A Review
Author(s): Michael D. Levin, MD, PhD, DSc*
The definition of "Megacolon" is still subjective since the methods of determination are not based on reliable limits of the norm. The literature review consists of three parts. The first part for analysis, a method was selected that allows to differentiate 3 degrees of megacolon, regardless of age. The second part analyzes children from 1 to 6 years of age, in whom an involuntary delay in defecation leads to overflow of the rectum and, with a subsequent painful attempt at defecation, to a conscious delay. Thus, a vicious circle arises, because of which a functional megacolon (FM) develops. The obstructive nature of FM has been proven, and two variants of its pathogenesis. The third part consisted of patients with anorectal malformations. The cause of megacolon is a sharp narrowing of the ectopic anus. The dissection of the stenotic ring in patients with visible fistulas can completely prevent the development of megacolon. After the cutback procedure, boys with perineal fistulas do not experience fecal incontinence, and mild constipation resolves with time. After pull-through surgery, regardless of access, there is severe constipation with megacolon and/or fecal incontinence. In these cases, the violation of fecal retention and defecation is due to the destruction of the ectopic anal canal, without which these functions cannot be restored. A method for determining megacolon and anal canal function in children of different ages is described. This made it possible to establish that acquired megacolon is always of an obstructive nature, either over constriction or because of a dysfunction of the anal canal.