Prolapse of the Intussuseeptant.—In extreme eases the invagination may go on; the intussusceptum proceeds down the colon and rectum and may be felt in the latter like a portio uteri; finally it may even pro lapse through the anus, and will then give a pieture similar to a rectal prolapse, with this difference, however, that the mucous membrane of the prolapsed gut is not directly continuous with the mucous covering of the anus and that we are able to carry our finger around the prolapsed part within the rectum. The intussuseeptunt will naturally pull down more and more of the gut into the intussuscipiens, which will be most ominous in those cases in which the colon has a free mesentery. In these instances we cannot differentiate between invagination and prolapse, and the whole colon may come down as a prolapse at the apex of which we observe the invaginated ileoeTeal valve.
Treatment in these cases of prolapsed invagination which we cannot replace is identical with that for gangrenous prolapse of the rectum.
(e) Prolapse of the _Taus et Rectum (See Fisehl, Prolapse of the Rectum, vol. iii.) the saine conditions as invagination, we may observe in children the reduplication of the rectum into itself and the protrusion from the anus, the genesis of which is the same as that of invagination (prolapses recti) (Fig. 117). When only the mucous lining of the anus protrudes, we speak of a prolapse of the anus (Fig. 145). Between this and the prolapse of the entire colon to the ileoca‘cal valve all stages arc possible (see Invagination). In large prolapses the peritoneum is pulled down as well, and into these peritoneal pockets intestinal loops may enter (rectal hernia).
Etiology.—The mesentery of the colon and the sigmoid flexure being often freer and longer in children, will favor the formation of pro lapse as it does that of invagination. Added to this, is a vertical position of the coccyx and also of the reet um (on account of the insufficient tilting of the pelvis in the beginning of the erect position), sometimes also a congenitally deep Douglas's pouch (Hoffmann), so that we may regard the majority of cases of prolapse as the consequence of a ital predisposition together with an insufficient adaptation to the erect carriage. Loosening of the pelvic floor through the loss of fat and sening of the muscular torus and increased infra-abdominal pressure are the most evident etiological as well as causative factors. Should polypi or hemorrhoids be present then these will also favor in vagination, the same as In tumors of the intestinal mucosa higher up (see Sarcoma).
The most dangerous time for the formation of these prolapses is the beginning of the stage when the body is carried erect, i.e., between the first and third year of life. The rectum, which is still adapted to the horizontal position, is now placed vertically, and increased demands arc made upon its ligaments and the pelvic floor. This will be lessened again when the pelvis is tilted (lumbar lordosis) after the spine has found its final equilibrium for the erect carriage. The highest degrees arc repre sented by those intermediate stages between intussusception and prolapse, in which the whole colon comes down owing to its free mesentery, and in which Bauhin's valve appears at the apex of the prolapse, and through which the small intestine may also prolapse. We have seen such a case in a child of one month, which was later found to be a cretin and showed other defects of development (permanent cure by two paraffin bars).
The first conditions (weakening of the pelvic floor) are found in atrophic infants suffering from gastrointestinal disturbances. Frequent stools, tenesmus, rapid loss of fat, and wasting are directly responsible for this process. In older children, of from two to four years, digestive disturbances or straining on the chamber are to be blamed. Later on when the pelvis is tilted (physiologic lumbar lordosis) and when the rectum moves further backwards in the erect posture, as corresponds to our origin from the quadruped mammalia, then the prolapse in chil dren will either have disappeared or will only he very rarely found.
Prognosis.—From this we might assume a very favorable prognosis. If we can keep these children alive until after the fifth year of life, then the prolapse will usually heal spontaneously, if this is not prevented by congenital conditions or tumors.
The symptoms from the exposure of the rectal mucosa and from secondary changes (hemorrhoidal tumors) arc such that their frequent recurrence or when we are unable to keep the prolapse back will endanger the child's life. The sphincter ani and the muscular pelvic floor may he so weakened and distended that they are no longer able to retain the replaced prolapse. We have also observed four eases in which a long persistence of the prolapse led to occlusion of the bowel and to necrosis which was similar to that observed in invagination.