Variant 3: Suspected proctitis or pouchitis. Initial imaging. Proctitis, inflammation of the rectum, is a common manifestation of inflammatory bowel disease (ulcerative colitis and CD). Other causes include infections (gonorrhea, chlamydia, herpes simplex virus, HIV/acquired immunodeficiency syndrome), radiation, and ischemia. Patients present with rectal pain, discomfort, tenesmus, purulent discharge, abdominal pain, and urgency. In most patients, imaging is not required. However, if a more complex disease is clinically suspected, imaging may be indicated to define the extent of disease and/or complications. An ileal pouch anal anastomosis (IPAA), also known as a J-pouch, is the most common surgical approach for creating a continent reservoir following total proctocolectomy. This is typically performed in a two-stage procedure in patients with ulcerative colitis or familial adenomatous polyposis. Pouchitis is a common complication of IPAA, occurring in approximately 20% of patients within 1 year of surgery and 50% of patients within 10 years of surgery [46]. Pouchitis may be caused by primary infection or an immune response to an altered microbiome in the pouch lumen or mucosa. Patients may present with increased stool frequency and fluidity, tenesmus, incontinence, pain, malaise, fever, or bleeding. The symptoms of pouchitis overlap with other postoperative complications, such as dehiscence and abscess, as well as occult CD such as in patients that have presumed ulcerative colitis with undiagnosed CD or subsequently developed CD [47]. Imaging is an important complementary technique to endoscopy with biopsy to accurately diagnose and manage inflammation in the pouch. CT Enterography CT enterography techniques provide better visualization of the small bowel compared with routine CT.
Anorectal Disease. Variant 3: Suspected proctitis or pouchitis. Initial imaging. Proctitis, inflammation of the rectum, is a common manifestation of inflammatory bowel disease (ulcerative colitis and CD). Other causes include infections (gonorrhea, chlamydia, herpes simplex virus, HIV/acquired immunodeficiency syndrome), radiation, and ischemia. Patients present with rectal pain, discomfort, tenesmus, purulent discharge, abdominal pain, and urgency. In most patients, imaging is not required. However, if a more complex disease is clinically suspected, imaging may be indicated to define the extent of disease and/or complications. An ileal pouch anal anastomosis (IPAA), also known as a J-pouch, is the most common surgical approach for creating a continent reservoir following total proctocolectomy. This is typically performed in a two-stage procedure in patients with ulcerative colitis or familial adenomatous polyposis. Pouchitis is a common complication of IPAA, occurring in approximately 20% of patients within 1 year of surgery and 50% of patients within 10 years of surgery [46]. Pouchitis may be caused by primary infection or an immune response to an altered microbiome in the pouch lumen or mucosa. Patients may present with increased stool frequency and fluidity, tenesmus, incontinence, pain, malaise, fever, or bleeding. The symptoms of pouchitis overlap with other postoperative complications, such as dehiscence and abscess, as well as occult CD such as in patients that have presumed ulcerative colitis with undiagnosed CD or subsequently developed CD [47]. Imaging is an important complementary technique to endoscopy with biopsy to accurately diagnose and manage inflammation in the pouch. CT Enterography CT enterography techniques provide better visualization of the small bowel compared with routine CT.