What are the diagnosis criteria and management options for Ulcerative Colitis (UC)?

Ulcerative Colitis Diagnosis Criteria and Management

The diagnosis of ulcerative colitis requires a combination of clinical history, laboratory tests, endoscopy with histopathology, and exclusion of infectious causes, as there is no single gold standard diagnostic test. 1

Diagnostic Criteria

Clinical Presentation

• Typical symptoms include bloody diarrhea with or without mucus, rectal bleeding, stool consistency and frequency changes, urgency, tenesmus, and variable degrees of abdominal pain often relieved by defecation 2
• Medical history should document recent travel, possible infectious contacts, medication use (particularly antibiotics and NSAIDs), smoking status, sexual behavior, family history of IBD or colorectal cancer, and previous appendectomy 2, 3
• Physical examination findings depend on disease severity - patients with mild to moderate disease may have unremarkable examinations except for blood on rectal examination, while those with severe disease may present with fever, tachycardia, weight loss, abdominal tenderness, distension, and reduced bowel sounds 2

Laboratory Evaluation

• Initial laboratory tests should include full blood count, inflammatory markers (CRP), electrolytes, liver function tests, and stool samples for microbiological analysis 2
• Fecal calprotectin is an accurate marker of colonic inflammation and correlates with disease activity 2
• In patients with severe clinical activity, elevated CRP is generally associated with elevated ESR, anemia, and hypoalbuminemia, which can serve as predictive biomarkers for colectomy risk in acute severe colitis 2, 3

Endoscopic Evaluation

• Ileocolonoscopy with biopsy is essential for definitive diagnosis 1
• For reliable diagnosis, a minimum of two biopsies from at least five sites around the colon (including the rectum) and the ileum should be obtained 2
• Inflammation typically begins at the anal verge and extends proximally in a continuous, confluent, and concentric fashion with clear demarcation between inflamed and normal areas 2
• In patients with acute severe colitis, flexible sigmoidoscopy rather than full colonoscopy is recommended to confirm diagnosis and exclude infection 2
• The Mayo scoring system is commonly used to assess endoscopic severity, with scores ranging from 0 (normal) to 3 (spontaneous bleeding) 2

Histopathological Assessment

• Basal plasmacytosis is the earliest diagnostic feature with the highest predictive value for UC diagnosis 2
• Established disease shows widespread crypt architectural distortion, mucosal atrophy, diffuse transmucosal inflammatory infiltrate with basal plasmacytosis, and active inflammation causing cryptitis and crypt abscesses 2
• A decreasing gradient of inflammation from distal to proximal favors UC diagnosis 2
• Histological healing is distinct from endoscopic mucosal healing, and persistent histological inflammation may be associated with adverse outcomes 2

Management

Treatment Based on Disease Extent and Severity

Mild to Moderate Disease

• For proctitis (distal disease), topical 5-aminosalicylic acid (5-ASA) drugs are the first-line treatment 4
• For more extensive disease, a combination of oral and topical 5-ASA is recommended 4
• Oral corticosteroids should be considered for patients who fail to respond to 5-ASA compounds 5

Moderate to Severe Disease

• Systemic corticosteroids are effective for inducing remission but not for maintenance therapy 5
• For steroid-dependent disease, thiopurines (azathioprine/6-MP), anti-TNF agents (infliximab, adalimumab, golimumab), vedolizumab, or methotrexate should be considered 1
• Infliximab has shown efficacy in inducing clinical response, clinical remission, and mucosal healing in patients with moderately to severely active UC who have had an inadequate response to conventional therapy 6
• Vedolizumab is effective for inducing and maintaining clinical response and remission in patients with moderate to severe UC 7

Severe Acute Colitis

• Patients with severe UC need hospitalization for treatment with intravenous steroids 4
• In steroid-refractory cases, rescue therapy with either calcineurin inhibitors (cyclosporine, tacrolimus) or infliximab should be considered 1, 4
• If medical therapy fails, colectomy may be necessary 4

Maintenance Therapy

• Once remission is achieved, appropriate maintenance therapy should be continued 4
• 5-ASA compounds are effective for maintaining remission in mild to moderate UC 5
• Immunomodulators (azathioprine/6-MP) are used for maintaining remission in patients with more severe disease or those who are steroid-dependent 5
• Biological agents (infliximab, vedolizumab) have demonstrated efficacy in maintaining remission 6, 7

Monitoring Response to Treatment

• Response should be determined by a combination of clinical parameters, endoscopy, and laboratory markers such as CRP and fecal calprotectin 3
• In patients who clinically respond to medical therapy, mucosal healing should be assessed endoscopically or by fecal calprotectin approximately 3-6 months after treatment initiation 1
• Mucosal healing is associated with reduced risk of colectomy and lower inflammation at 5 years 3

Surgical Management

• Indications for emergency surgery include refractory toxic megacolon, colonic perforation, or severe colorectal bleeding 4
• Elective colectomy should be considered in patients with refractory disease or high-grade dysplasia 8

Cancer Surveillance

• Patients with extensive colitis have higher risk of colectomy and colorectal cancer compared to those with limited disease 3
• Regular surveillance colonoscopies should be scheduled at intervals that depend on risk stratification 8

Common Pitfalls and Caveats

• There is no gold standard for UC diagnosis; it is established through a combination of clinical, laboratory, imaging, and endoscopic parameters including histopathology 2
• Infectious causes must be excluded before confirming diagnosis, particularly C. difficile 2, 3
• Disease extent can change after diagnosis - up to half of patients with proctitis or proctosigmoiditis will develop more extensive disease over time 3
• Repeat endoscopy with histopathological review may be necessary if diagnostic doubt remains 2
• Non-selective NSAIDs may exacerbate the disease and should be avoided 2
• Atypical presentations include rectal sparing and patchiness of disease at initial presentation in pediatric patients or in medically treated UC, cecal or ascending colon inflammation in left-sided UC, and backwash ileitis in patients with severe ulcerative pancolitis 9