From the Guidelines
Diagnosing ulcerative colitis requires a comprehensive approach involving multiple tests, with the gold standard being colonoscopy with biopsies, as recommended by the most recent guidelines 1.
Key Steps in Diagnosis
- Initially, a doctor will review the patient's medical history and symptoms, which typically include bloody diarrhea, abdominal pain, urgency to defecate, and weight loss.
- Laboratory tests are essential, including complete blood count to check for anemia, inflammatory markers like C-reactive protein and erythrocyte sedimentation rate, and stool tests to rule out infections.
- The procedure of colonoscopy with biopsies allows direct visualization of the colon to identify characteristic continuous inflammation starting from the rectum and extending proximally, revealing erythema, friability, granularity, and ulcerations of the mucosa.
- Histological examination of biopsies confirms the diagnosis by showing crypt abscesses, distortion of crypt architecture, and inflammatory cell infiltration limited to the mucosa.
Additional Considerations
- Additional imaging studies like CT scans or MRI may be used to assess disease extent and complications.
- In some cases, sigmoidoscopy might be preferred initially if the colon is severely inflamed.
- Differential diagnosis must exclude Crohn's disease, infectious colitis, and microscopic colitis.
- The diagnosis is ultimately based on the combination of clinical presentation, endoscopic findings, histology, and exclusion of other conditions, as outlined in recent guidelines 1.
Recent Guidelines
- The British Society of Gastroenterology consensus guidelines on the management of inflammatory bowel disease in adults recommend a full ileocolonoscopy to delineate disease extent, severity of inflammation, and to exclude Crohn’s disease 1.
- The ECCO-ESGAR guideline for diagnostic assessment in IBD part 1 also emphasizes the importance of ileocolonoscopy with biopsies for a reliable diagnosis of UC and CD 1.
From the Research
Diagnostic Markers for Ulcerative Colitis
To diagnose ulcerative colitis, several markers can be used, including:
- Erythrocyte sedimentation rate (ESR) [(2,3,4)]
- C-reactive protein (CRP) [(2,3,4,5)]
- Adenosine deaminase (ADA) 3
- C-reactive protein-albumin (CRP/ALB) ratio 5
- Platelet-lymphocyte ratio (PLR) 5
- Neutrophil-lymphocyte ratio (NLR) 5
Assessment of Disease Activity
The severity of ulcerative colitis can be assessed using various parameters, including:
- Clinical symptoms 4
- Endoscopic activity 5
- Laboratory tests such as ESR and CRP [(2,4)]
- The CRP/ALB ratio has been shown to be a useful predictor of disease activity 5
Comparison of Diagnostic Markers
Studies have compared the usefulness of different markers in assessing the severity of ulcerative colitis, including:
Diagnostic Criteria
The Truelove and Witts Criteria (TWC) are traditionally used to assess ulcerative colitis activity, with ESR as a component 2. However, CRP has been proposed as a more practical alternative to ESR in defining UC presentation severity 2.