The rectum is the final segment of the large intestine, serving as a temporary reservoir for stool before elimination. A rectal perforation occurs when a tear or hole develops in the wall of the rectum, compromising its structural integrity. This breach is a serious medical emergency because it allows the contents of the rectum—including bacteria and fecal matter—to leak into the surrounding pelvic or abdominal cavity. Such contamination can rapidly lead to severe, life-threatening infection and sepsis, necessitating immediate medical intervention.
Understanding Rectal Perforation
The rectum is situated deep within the pelvis. A perforation can occur in two distinct zones: the intraperitoneal or the extraperitoneal space.
The upper portion of the rectum is partially covered by the peritoneum, the membrane lining the abdominal cavity. A tear in this area is an intraperitoneal perforation, which is generally more dangerous. This injury leads to widespread spillage of infectious material into the abdominal cavity, causing generalized peritonitis.
The lower two-thirds of the rectum are not covered by the peritoneum and are considered extraperitoneal. A perforation here results in the leakage of contents into the pelvic tissues and the retroperitoneal space. Although less immediately dramatic, extraperitoneal perforations can cause severe localized infection, including abscesses.
Primary Causes and Associated Risk Factors
Rectal perforations are categorized as iatrogenic, traumatic, or disease-related.
Iatrogenic Causes
Iatrogenic injuries are those caused inadvertently by medical procedures. These injuries often occur during endoscopic procedures like colonoscopy or rigid sigmoidoscopy, especially when therapeutic interventions such as polyp removal are performed. The typical mechanisms include mechanical trauma from the scope or thermal injury from electrocautery.
Traumatic Causes
Traumatic causes include both blunt and penetrating injuries. Penetrating trauma is frequently associated with gunshot or stab wounds to the lower abdomen, pelvis, or buttocks. Blunt trauma, such as that sustained in high-impact accidents, can cause rectal tears when associated with severe pelvic fractures. Foreign body insertion is also a cause of traumatic rectal perforation.
Disease-Related Causes
Disease-related perforations occur when underlying health conditions weaken the rectal wall. Conditions causing severe inflammation and necrosis, such as advanced colorectal cancer, severe diverticulitis, or inflammatory bowel diseases (Crohn’s disease or ulcerative colitis), can lead to spontaneous rupture. Bowel obstruction, which causes immense pressure and reduced blood flow, can also result in perforation due to ischemic necrosis. Risk factors like a history of radiation therapy or previous rectal surgery can compromise the tissue and increase susceptibility to injury.
Recognizing the Signs and Emergency Diagnosis
Recognition relies on identifying acute and severe symptoms requiring immediate medical attention. Patients typically experience the sudden onset of severe abdominal pain, often localized to the lower abdomen or pelvis, which rapidly worsens. This intense pain is accompanied by signs of systemic infection, such as high fever and chills. The development of peritonitis, characterized by a rigid abdomen and tenderness, is a hallmark sign of contamination.
The diagnostic process must be swift to confirm the perforation. Initial laboratory tests assess the body’s response to infection, often showing an elevated white blood cell (WBC) count and increased lactate levels, suggesting sepsis. Imaging studies are crucial for locating the injury. A plain abdominal X-ray may be performed first to look for pneumoperitoneum, the presence of free air under the diaphragm, indicating air has escaped the bowel.
The computed tomography (CT) scan is the most sensitive test for diagnosing a perforation and identifying its precise location. A CT scan can visualize a defect in the rectal wall, track extraluminal air, and show signs of inflammation. For extraperitoneal injuries, CT is valuable as it detects air or fluid accumulating in the pelvic or retroperitoneal spaces.
Medical Management and Long-Term Recovery
The definitive treatment for a rectal perforation is emergency surgical intervention. The primary goals are to control the source of contamination, repair the tear, and manage the infectious process. The surgeon first thoroughly cleans the abdominal or pelvic cavity, a process known as lavage, to remove leaked fecal matter and bacteria. The perforation is then addressed, often involving a direct primary repair if the injury is small and detected early.
For larger injuries or those with significant contamination, the surgeon often performs a fecal diversion. This involves creating a temporary or permanent stoma (colostomy or ileostomy) to reroute the fecal stream away from the injured area, allowing it to heal. This diversion brings a portion of the intestine to the surface of the abdomen where a pouch collects waste. A stoma is frequently necessary for complex tears or when the patient is unstable.
Immediate post-operative care focuses on broad-spectrum intravenous antibiotics and pain management. Recovery often requires a hospital stay of several days to a week while bowel function returns. If a temporary ostomy was created, its reversal is typically planned several months later once the injury has fully healed. Full recovery can take several weeks to months, involving a gradual return to normal diet and activity.