Elliot K. Fishman M.D.
Professor of Radiology, Surgery, Oncology and Urology
Johns Hopkins Hospital

Click here to view this module as a video lecture.

“Post colonoscopy complications that maybe seen in patients in the ED include bowelperforation, postprocedural hemorrhage, postpolypectomy syndrome, splenic injury, appendicitis, and diverticulitis. CT is the imaging modality of choice in the ED, allowing rapid detection of these various complications. Although post colonoscopy complications are infrequent, radiologist awareness of these complications and the associated imaging findings is essential for optimal diagnosis and prompt management.”
Acute Abdominal Pain Following Optical Colonoscopy: CT Findings and Clinical Considerations
Robin B. Levenson, Katherine M. Troy, Karen S. Lee
AJR 2016; 207:W33–W40

“The NCCN Guidelines for CRC Screeningcurrently recommend that screening for average-risk individuals beginning at 50 years of age. The American Cancer Society (ACS) 2018 and US Preventive Services Task Force 2021 guidelines recommend that adults aged 45 years and older with an average risk of CRC undergo regular screening with either a high-sensitivity stool-based test or a structural (visual) examination, depending on patient preference and test availability; and all positive results on non colonoscopy screening tests should be followed up with timely colonoscopy.”
CT imaging findings of complications of optical colonoscopy
Abhishek Keraliya · Hei Shun Yu · Jennifer W. Uyeda
Emergency Radiology (2022) 29:915–923

“Colonoscopy is one of the most commonly performed endoscopic procedures and remains the most commonly used screening modality method for colorectal cancer (CRC) screening in the USA. Although serious complications of fiberoptic colonoscopy are uncommon due to technical advances, due to increasing number of colonoscopy procedures, post-procedural complications are not uncommonly encountered in the routine clinical practice. Also, as some of the post-colonoscopy complications are life threatening, it is important to diagnose them early so that timely treatment measures can be taken to decrease mortality and morbidity.”
CT imaging findings of complications of optical colonoscopy
Abhishek Keraliya · Hei Shun Yu · Jennifer W. Uyeda
Emergency Radiology (2022) 29:915–923

“The most common complicationsof optical colonoscopy are hemorrhage and largebowel perforation. Less common complications include splenic injury, postpolypectomy syndrome, appendicitis, and acute diverticulitis. Unusual complications of colonoscopy include pneumothorax, omental infarction, liver abscess, septicemia, mesenteric tears, intussusception, and colonic volvulus.”
CT imaging findings of complications of optical colonoscopy
Abhishek Keraliya · Hei Shun Yu · Jennifer W. Uyeda
Emergency Radiology (2022) 29:915–923

“Complications after optical colonoscopy thatcan be identified on CT include bowel perforation (both macro- and microperforation),postprocedural hemorrhage, postpolypectomysyndrome, appendicitis, and diverticulitis.Given that optical colonoscopy is a commonprocedure, radiologist awareness of thepotential colonoscopy complications seen atCT is imperative for appropriate diagnosisand subsequent patient management.”
Acute Abdominal Pain Following Optical Colonoscopy: CT Findings and Clinical Considerations
Robin B. Levenson, Katherine M. Troy, Karen S. Lee
AJR 2016; 207:W33–W40

“Post-colonoscopy bowel perforation is a rare but serious complication of diagnostic colonoscopy and occurs in 0.005 to 1% of cases. Colonoscopy done fortherapeutic procedures such as polyp removal, dilation of strictures, or laser ablative procedures is associated with higher rate of perforation and can be seen in up to 3% ofpatients.”
CT imaging findings of complications of optical colonoscopy
Abhishek Keraliya · Hei Shun Yu · Jennifer W. Uyeda
Emergency Radiology (2022) 29:915–923

“The most common site for diagnosticcolonoscopy perforation is the sigmoid colon due to acute angulation of the rectosigmoid junction. As diverticular disease and polyps more commonly affect the sigmoid colon, the incidence of mechanical and thermal injury in the sigmoid colon is higher.”
CT imaging findings of complications of optical colonoscopy
Abhishek Keraliya · Hei Shun Yu · Jennifer W. Uyeda
Emergency Radiology (2022) 29:915–923

“Bowel perforation may occur relativelyrarely from optical colonoscopy, occurringin ≤ 0.3% of screening colonoscopiesup to 0.03–0.8% for diagnostic colonoscopy and 0.15–3% for therapeutic colonoscopy. At least three major mechanisms havebeen suggested: direct trauma from diagnosticcolonoscopy, barotrauma from over insufflation,and perforation from therapeutic intervention.”
Acute Abdominal Pain Following Optical Colonoscopy: CT Findings and Clinical Considerations
Robin B. Levenson, Katherine M. Troy, Karen S. Lee
AJR 2016; 207:W33–W40

“At CT, patients with macroperforationafter optical colonoscopy may have a large amount of free gas. Extraluminal contrast material from oral or rectal administration may also be seen, if administered, potentially directly extravasating from the site of bowelperforation. When there is concern for perforation, any enteric contrast material given should be iodinated and water-soluble . If the surgical team requests rectalcontrast material administration, it should be given carefully, preferably via Foley catheter. Many institutions, including ours, have eliminated the routine use of oral contrast material in the ED to avoid delay in imaging.”
Acute Abdominal Pain Following Optical Colonoscopy: CT Findings and Clinical Considerations
Robin B. Levenson, Katherine M. Troy, Karen S. Lee
AJR 2016; 207:W33–W40

“Intraluminal bleeding as a complication of optical colonoscopy typically occurs after a biopsy and polypectomy and is only rarely seen in the setting of a purely diagnostic examination. The incident of postpolypectomy bleeding ranges from 0.001–2%. Intraluminal bleeding can also result from inadvertent biopsy of a vascular lesion such as hemangioma, arteriovenous malformation, or a prominentmucosal vein associated with angiodysplasia.”
CT imaging findings of complications of optical colonoscopy
Abhishek Keraliya · Hei Shun Yu · Jennifer W. Uyeda
Emergency Radiology (2022) 29:915–923

“Intraluminal hemorrhage is the most commonmajor complication after optical colonoscopy. Although most patients do not undergo CT, their diagnosis and management is managed by the gastroenterologist (and other clinicians) . Postcolonoscopy hemorrhage has been reported to occur in 1–6 of every 1000 colonoscopies. The rate is greater in patients who have undergone polypectomy (2.1– 3.7 per 1000 examinations, compared with 8.7 per 1000 examinations). Occasionally, a vascular lesion (i.e., hemangioma, arteriovenous malformation, or a prominent mucosal vein) may be biopsied with subsequent bleeding. Hemorrhage can occur immediately after the procedure or up to several weeks thereafter. Passage of a large amount of blood after optical colonoscopy is concerning for active hemorrhage. Delayed bleeding after polypectomy may be seen in 0.3–1.2% of patients who have undergone polypectomy and may occur 1–15 days after the procedure.”
Acute Abdominal Pain Following Optical Colonoscopy: CT Findings and Clinical Considerations
Robin B. Levenson, Katherine M. Troy, Karen S. Lee
AJR 2016; 207:W33–W40

“Splenic injury from optical colonoscopyis a rare complication with an incidenceof 0.0005–0.017% but with a mortality rateof 5%. A retrospective review of 296,248 colonoscopies by Kamath et al.found four cases of splenic injury (incidenceof 0.001%). Only approximately 100 cases ofsplenic injury from optical colonoscopy havebeen reported in the literature to our knowledge.”
Acute Abdominal Pain Following Optical Colonoscopy: CT Findings and Clinical Considerations
Robin B. Levenson, Katherine M. Troy, Karen S. Lee
AJR 2016; 207:W33–W40

“A retrospective review by Ha andMinchin, evaluating surgical findings in patients with splenic injury after colonoscopy (68.2% of who underwent preoperative CT), found subcapsular hematoma to be the most (common finding (56.1%), followed by laceration (47%) and rupture 33%). The frequency of these findings would presumably be similar on imaging. These complications are often accompanied by either small or large volume hemoperitoneum, depending on the severity of the splenic injury. CT findings in the multicenter review by Fishback et al. included subcapsular hematoma alone (45%), subcapsular and perisplenic hematoma (37%), laceration (27%), and splenic pseudoaneurysm.”
Acute Abdominal Pain Following Optical Colonoscopy: CT Findings and Clinical Considerations
Robin B. Levenson, Katherine M. Troy, Karen S. Lee
AJR 2016; 207:W33–W40

“Splenic injury during colonoscopy is very rare but mayresult in significant hemorrhage. Proposed mechanisms of splenic injury include excessive traction/ torsion of the splenocolic ligament, direct trauma from navigation of splenic flexure leading to capsularavulsion, and protracted direct compression on spleen by colonoscope. Decreased motility of the spleen due to adhesions from prior surgery, previous pancreatitis, or inflammatory bowel disease and excess fragility because of splenomegaly due to hematological, infectious,and infiltrative diseases predispose to splenic injury during colonoscopy. Operator dependent risk factors for splenic injury include directinjury and excessive traction on the splenocolic ligament while navigating the splenic flexure. The common signs and symptoms of splenic injury are abdominal pain, left shoulder pain due to diaphragmatic irritation, peritoneal irritation, and hypotension.”
CT imaging findings of complications of optical colonoscopy
Abhishek Keraliya · Hei Shun Yu · Jennifer W. Uyeda
Emergency Radiology (2022) 29:915–923

However, a colonoscopy is the most common cause of iatrogenic splenic injury (in comparison to other procedures or surgeries). The risk factors for splenic injury are both patient and operator dependent. Patient-dependent factors include pre-existing enlargement of the spleen, surgical adhesions, inflammatory bowel disease, and severe diverticular disease. Operator dependent factors include placing the patient on their back, excessive traction, over sedation, slide by advancement, and applying excessive external pressure. Despite these factors, it is still difficult to discern if the complication is unpredictable or directly related to technical factors given rarity of this complication.

Splenic injury is a rare but serious complication of colonoscopy. Since the mid-1970s, 68 splenic injuries during colonoscopy including our 2 cases have been described. With the increasing use of colonoscopy, endoscopists, surgeons, and radiologists are more likely to encounter this unusual complication. Any cause of increased splenocolic adhesions, splenomegaly, or underlying splenic disease might be a predisposing factor for splenic injury during colonoscopy. However, it can occur in patients without significant adhesions or underlying splenic pathology. The diagnosis is often described in the literature as delayed, because many physicians are not aware of this complication of colonoscopy. Although computerized tomography is highly sensitive, knowledge of this complication is the best tool to aid in early diagnosis. Patients with abdominal pain, hypotension, and a drop in hematocrit without rectal bleeding after colonoscopy should be suspected of having splenic injury.
Splenic injury after elective colonoscopy.
Sarhan M, Ramcharan A, Ponnapalli S.
 JSLS. 2009;13(4):616-619.

The diagnosis is often described in the literature as delayed, because many physicians are not aware of this complication of colonoscopy. Although computerized tomography is highly sensitive, knowledge of this complication is the best tool to aid in early diagnosis. Patients with abdominal pain, hypotension, and a drop in hematocrit without rectal bleeding after colonoscopy should be suspected of having splenic injury.
Splenic injury after elective colonoscopy.
Sarhan M, Ramcharan A, Ponnapalli S. 
JSLS. 2009;13(4):616-619.