Cloacal deformity of the perineum with an absence of the perineal body and large communication of the vagina with the anal canal
Ingested foreign bodies: Several small, sharp particles ingested voluntarily (such as nails eaten by psychiatric patients), or accidentally (fish or chicken bones, walnut husks, fragments of glass, toothpicks, dentures) can reach the rectum and become trapped in the rectal wall or sphincter muscles, leading to perforation or abscess. Drugs wrapped in plastic packets are a new type of ingested foreign body. The package may break during endoscopic or surgical attempts to remove it, possibly causing a life-threatening drug overdose.
Foreign bodies introduced through the anus: An amazing variety of oblong (phallic-like) objects have been introduced into the rectum and remained trapped above the anal sphincters – the most frequently found are bottles, plastic dildos and vibrators, vegetables, electric light bulbs, pens, and glasses – usually in an attempt at autoerotism or during sexual assault. Sometimes thermometers can get lost in the rectum when measuring temperature in children and may break, causing penetrating injuries to the rectal wall.
Sexual assault via the anus: In both men and women trauma may be the result of too vigorous anal sex acts voluntarily accepted by both partners or may be a criminal act sometimes performed on children (particularly young boys).
Pneumatic injuries: Explosion of the rectum and colon, provoking severe abdominal pain and shock, can be caused by a sudden increase in intrarectal pressure if compressed air is injected through the anus; this may be done as a foolish and criminal joke.
Iatrogenic diagnostic/therapeutic injuries: These can be the result of:
Enema (the enema nozzle may cause mucosal laceration and rectovaginal fistulas, or using water that is too hot can severely burn the mucosa)
Rectal biopsy, which can cause bleeding and perforation
Diathermy polypectomy, which can cause colonic gases (methane, hydrogen sulfide, hydrogen) to explode
Surgery for anal fissures, hemorrhoids, fistulas, and abscesses
Surgery for prostate, bladder, and uterine diseases
Penetrating injuries: Sharp anorectal injuries caused by stab or gunshot wounds should be classified as intraperitoneal and extraperitoneal wounds; the former are more frequent than the latter.
Stab wounds involving the anus or the extraperitoneal rectum are rare in Western countries but may arise as part of a complex anoperineal trauma in car or motorcycle accidents. Penetrating stab wounds involving the intraperitoneal rectum may be produced by knives or daggers and need to be treated like any colonic injury.
Gunshot wounds are relatively frequent in wartime because of the prone position assumed by soldiers while firing, and the extent of rectal damage depends on the ballistic properties of the projectile. High-velocity bullets (military) produce a small entrance hole but extensive tissue damage, multiple perforations, and a large exit wound, whereas low-velocity bullets (civilian use) are often retained in the tissues.
Rectal impalement: This was used to torture and kill enemies in ancient times, but today it can still occur following falls onto pointed objects. This may happen, for example, in agricultural workers who accidentally fall onto a tools or a fence post with the legs astride, or in an accidental fall by those participating in sports involving climbing or jumping. The penetrating trauma can involve the anus, the anal sphincters, and the rectal wall and may extend to the sacrum and coccyx, perineum, prostate, urethra, and bladder, as well as the intraperitoneal organs, especially the small and large bowels. Such severe trauma has also been described as the outcome of criminal acts.
Inspection and digital exploration of the anal canal can easy demonstrate the outcome of an anal trauma (Figs. 32.2 and 32.3). Today, the use of 2D or 3D transanal ultrasound is a cornerstone in the diagnosis of any anal trauma and is most useful if shown in three dimensions.
Keyhole deformity of the anus following surgery for anal fistula
Outcome of accidental anal trauma resulting in a prolapsed rectal mucosa, patulous anus, and a scar replacing the anoderm
Enquiry about the patient’s history and an exploration of the perineum and abdomen are the first steps in assessing any anorectal trauma. Sometimes patients are reluctant to admit anal intercourse or autoerotism resulting in retention of foreign bodies. Perianal ecchymosis or laceration are usually present after any sexual assault, and sperm may also be found. Because of legal issues, special care must be taken to prove the assault with photographs or stains, allowing eventual identification of the perpetrator after rape, for instance.
A retained foreign body may be felt by lubrication anal digital exploration, although in most cases the foreign body migrates distally into the rectosigmoid colon. An abdominal radiograph can usually assist in the diagnosis. A colonoscopy could be necessary to diagnose and treat a retained foreign body.
Abdominal pain, tenderness, ileus, and high temperature after a rectal trauma suggest perforation and peritonitis.
Minor anorectal trauma and retention of foreign bodies may cause anal and abdominal pain, rectal bleeding, and reflex urinary retention. The formation of a perianal/perirectal abscess can cause fever and induce severe pain sometimes leading to general sepsis.
Management and prognosis depend on the severity of the trauma. The American Association for the Surgery of Trauma attempted to quantify the severity of anal trauma and proposed the Rectal Injury Scaling System comprising five degrees of severity. McGrath et al. created a simpler classification of rectal injuries, between intraperitoneal and extraperitoneal rectal trauma, on the basis of rectal anatomy.