Colonoscopy is one of the most frequently used complementary exploration methods in gastroenterology. While it is generally considered low-risk, complications can arise, among which perforation is the most feared, even in the absence of surgical intervention. The incidence of iatrogenic colonic perforation could be as low as 0.016% of all diagnostic colonoscopy procedure ¹ and could reach up to 5% in interventional colonoscopies. ^{2 , 3}

The most commonly observed radiological translation is that of pneumoperitoneum (PNP). However, cases of pneumoperitoneum occurring without perforation following a diagnostic colonoscopy have been reported. ⁴ The management of colonic perforation remains a controversial issue, as it can be effectively handled through both surgical and non-surgical approaches. ^{4 , 5}

In this study, we present two cases of colonic perforation that occurred after colonoscopy, each with distinct manifestations and managed in different ways. The aim of our work is to detail the clinical presentations, diagnostic methods, and potential therapeutic options.

The case report presents two patients who underwent colonoscopies with potential colonic perforation complications. The strengths include detailed patient information, comprehensive clinical assessments, imaging diagnostics, and the demonstration of the effectiveness of conservative management in the first case. However, the second case lacks intraoperative photos, and the duration of monitoring is short for both cases.

Colonoscopy, a commonly performed procedure and the primary diagnostic tool for colorectal cancer, also plays a role in managing specific colorectal conditions, despite its relative safety, it does entail potential complications including colonic perforation, gastrointestinal bleeding, injury to intra-abdominal organs, and cardiopulmonary instability. ⁶

Although rare, Iatrogenic perforation carries a significant risk of morbidity and mortality. ⁷ The optimal management approach involves a collaborative effort among endoscopists, radiologists, and surgeons, requiring their prompt availability.

The incidence of colonic perforation varies between diagnostic and therapeutic colonoscopies, ^{8 , 9} with both sharing similar mechanisms such as mechanical injuries or barotrauma, but therapeutic colonoscopy presenting an additional potential risk of perforation, ¹⁰ resulting in an incidence ranging from 0.03% to 0.8% for diagnostic colonoscopy and 0.15% to 3% for therapeutic colonoscopy. ⁶

During diagnostic procedures, iatrogenic perforations are most frequently observed in the sigmoid colon and the rectosigmoid junction. This occurs because of direct mechanical injury caused by the shearing forces exerted by the colonoscope’s shaft or tip during insertion. ^{11 , 12} The risk of perforation can be further elevated by pericolic adhesions, which may result from previous gynecological surgeries or abdominal inflammation, as well as by severe diverticular disease. This increased risk is particularly notable when using large-caliber instruments ^{13 , 14} with excessive force.

In the realm of interventional colonoscopies, researchers have highlighted several noteworthy risk factors for iatrogenic colonic perforation. These influential factors encompass polypectomies, especially for polyps exceeding 20 mm in size, pneumatic dilatation for the management of strictures linked to inflammatory bowel diseases, the application of argon plasma coagulation, along with endoscopic mucosal resection and endoscopic submucosal dissection for colorectal neoplasms. Moreover, patient-related variables, including age, female sex, malnutrition, multiple comorbidities, a history of inflammatory bowel disease, and prior colon surgery, as well as the experience level of the endoscopist, play significant roles in the risk profile. Furthermore, it’s worth noting that the use of flexible sigmoidoscopy has also been associated with an elevated risk of perforation. ¹³

The risk of colonic perforation exists even in the absence of interventions, whether it occurs due to direct trauma to the colonic wall by the endoscope, shearing forces, or barotrauma. Regarding frequency, the sigmoid colon is the most commonly affected site in iatrogenic colonic perforation cases (53-64%), followed by the cecum (14-24%) and the ascending colon (24%), with notably lower incidences in the transverse colon, descending colon, and rectum. ⁶ Colonic perforations can be categorized into three types: intraperitoneal (the most prevalent scenario), extraperitoneal, or a combination of both. ⁶

The distribution of free air within distinct anatomical regions leads to the manifestation of symptoms and clinical signs, which depend on the type of perforation. ¹³ Typically, colonic perforation presents with acute abdominal pain, sometimes accompanied by fever. It may also exhibit signs of peritonitis such as abdominal tenderness, guarding or rigidity, abdominal distension, or, in the case of extraperitoneal perforation, subcutaneous emphysema. ¹³

The most common clinical feature of colonic perforation is the visualization of an extra-intestinal structure during the endoscopic examination. ² However, patients with colon perforation may present with symptoms and signs of peritonitis (primarily abdominal pain and tenderness) in the hours following the completion of colonoscopy, as seen in our third reported case. When perforation is suspected, an abdominal X-ray should be performed to rule out the presence of pneumoperitoneum. Other tests, such as computed tomography (CT) scanning and magnetic resonance imaging, are also highly useful for identifying the presence of free gas. ¹³

The use of a water-soluble contrast enema is rarely performed to detect or confirm a concealed perforation. In practice, patients can be diagnosed and treated for colonic perforation based on generalized peritonitis, even in the absence of radiological evidence of perforation.

While perforations usually occur during or within 24 hours of a colonoscopy, delayed perforations of the colon and rectum, as observed in our first case, have been reported. Therefore, physicians should consider colonic perforation if a patient presents with symptoms like fever, abdominal pain, or distension following the procedure, even if these symptoms manifest several days later. It is advisable to promptly and thoroughly assess and document any symptoms or signs indicative of iatrogenic perforation after an endoscopic procedure using a CT scan. ¹⁴

Following endoscopic resection, the presence of small gas bubbles may be observed, which do not necessarily indicate a genuine iatrogenic perforation. ¹⁵ Hence, it is crucial to consider radiological findings alongside endoscopic and clinical assessments. Due to the intricate nature of managing iatrogenic perforations, it is essential to have a multidisciplinary team comprising the endoscopist, radiologist, and surgeon available. The post-treatment follow-up for an iatrogenic perforation is contingent upon its type, location, and the patient’s clinical status, necessitating nearly obligatory hospitalization.

Indeed, the choice of treatment for iatrogenic perforation hinges on several factors, including the timing of diagnosis (whether intra- or post-procedure), the presence and nature of luminal contents (whether “clean” or not), the specific characteristics of the perforation (size and location), the patient’s overall health status, the expertise of the endoscopist, and the availability of closure devices. Therapeutic options encompass immediate endoscopic closure, a conservative approach, or surgical intervention. In cases where iatrogenic perforation is identified during the endoscopy, it is advisable, if feasible and reasonable, to complete the interventional procedure. Swift endoscopic closure, whenever possible, not only prevents peritonitis or mediastinitis but also reduces the necessity for surgical intervention. ^{16 – 18} A variety of endoscopic clips have been applied according to the size of iatrogenic perforation.

The conservative approach entails the administration of intravenous antibiotics, withholding oral intake, continuous monitoring of hemodynamics, and maintaining close interdisciplinary follow-up. ¹⁹ For malnourished patients or well-nourished individuals who won’t be able to eat for ≥ 7 days, parenteral nutrition is advised. ²⁰ If the conservative approach proves ineffective and the patient’s condition worsens, such as the development of septic or peritonitis symptoms, surgical intervention is strongly considered. ²¹ Early surgery is typically preferred for patients with large perforations, generalized peritonitis, ongoing sepsis, deteriorating clinical conditions, or after percutaneous drainage has failed. The choice between laparoscopy and open surgery for managing iatrogenic perforations primarily depends on the perforation’s location and the surgeon’s judgment. Minimally invasive laparoscopic treatment has become the favored surgical approach for colonic iatrogenic perforations due to its superior outcomes compared to open surgery. ⁷

Our two cases have demonstrated two different scenarios in the management and clinical presentation of colonic perforation following colonoscopy. This article has provided a comprehensive overview of iatrogenic colonic perforation, covering its incidence, risk factors, clinical presentation, diagnostic methods, and treatment options. It emphasizes the importance of a multidisciplinary approach and the consideration of various factors when determining the appropriate course of treatment. The article also highlights the increasing preference for minimally invasive laparoscopic procedures in managing colonic iatrogenic perforations.

Written informed consent for publication of their clinical details and clinical images was obtained from both patients.