From the Guidelines
The workup for rectosigmoid colitis should begin with a thorough history and physical examination, followed by laboratory tests including complete blood count, comprehensive metabolic panel, C-reactive protein, and erythrocyte sedimentation rate to assess inflammation. Stool studies are essential, including stool culture, Clostridioides difficile testing, ova and parasite examination, and fecal calprotectin to evaluate inflammation 1.
Key Components of the Workup
- Colonoscopy with biopsies is the gold standard diagnostic procedure, allowing direct visualization of the affected mucosa and collection of tissue samples for histopathological examination.
- Imaging studies such as CT scan or MRI of the abdomen and pelvis may be helpful to assess the extent of disease and rule out complications.
- Additional tests may include serological markers like ANCA and ASCA to differentiate between ulcerative colitis and Crohn's disease.
- Depending on clinical presentation, CMV PCR testing may be warranted, especially in immunocompromised patients. This comprehensive approach helps determine the specific cause of rectosigmoid colitis, whether infectious, inflammatory bowel disease, ischemic, radiation-induced, or medication-related, which is crucial for guiding appropriate treatment strategies.
Considerations for Treatment
- The AGA recommends treating patients with extensive mild-moderate UC with either standard dose mesalamine or diazo-bonded 5-ASA 1.
- For patients with proctosigmoiditis or proctitis, mesalamine suppositories or enemas may be preferred over oral 5-ASA therapy 1.
- Rectal corticosteroids may be considered for patients who are refractory to or intolerant of mesalamine suppositories or enemas 1.
Importance of Evidence-Based Practice
The workup and treatment of rectosigmoid colitis should be guided by the most recent and highest quality evidence, prioritizing morbidity, mortality, and quality of life as outcomes 1.
From the Research
Workup for Rectosigmoid Colitis
The workup for rectosigmoid colitis involves several steps to determine the extent and severity of the disease.
- The initial evaluation includes a thorough medical history and physical examination.
- Laboratory tests such as complete blood count, electrolyte panel, and liver function tests may be ordered to rule out other conditions and assess the overall health of the patient.
- Endoscopic examination, specifically rectosigmoidoscopy, is a crucial diagnostic tool for assessing disease activity and healing in patients with ulcerative colitis 2.
- Biopsies from the rectum and sigmoid colon can be taken during rectosigmoidoscopy to confirm the diagnosis and differentiate between inflammatory bowel disease (IBD) and other conditions 3, 4.
- However, it is essential to note that rectosigmoid histology may not be sufficient for a correct diagnosis of Crohn's disease or ulcerative colitis in children, and an ileocolonoscopy with biopsies may be necessary 3.
- Imaging studies such as computed tomography (CT) scans or magnetic resonance imaging (MRI) may be ordered to evaluate the extent of disease and rule out complications such as bowel obstruction or perforation.
- The diagnosis of ischemic proctosigmoiditis, a rare condition, can be made based on clinical presentation, endoscopic findings, and imaging studies, including CT scans and angiography 5.
Diagnostic Considerations
When evaluating a patient with suspected rectosigmoid colitis, it is crucial to consider the following:
- The clinical presentation and medical history to differentiate between inflammatory bowel disease, infectious colitis, and other conditions.
- The endoscopic and histologic findings to confirm the diagnosis and assess disease activity.
- The potential for complications, such as bowel obstruction or perforation, and the need for prompt medical attention.
- The importance of a thorough diagnostic workup to guide treatment decisions and improve patient outcomes.