CDAI Calculator

The Crohn's Disease Activity Index, usually abbreviated CDAI, is a research and clinical scoring system designed to summarize Crohn's disease activity. It combines symptoms recorded over seven days with examination findings and basic clinical measurements. The score was developed for trials and has become a familiar way to describe remission and degrees of active disease, but it does not replace a complete gastroenterology assessment. Eight weighted components contribute to the classic score. The seven-day number of liquid or very soft stools is multiplied by two. The sum of daily abdominal pain ratings is multiplied by five, and the sum of daily general well-being ratings is multiplied by seven. The number of recognized complications is multiplied by twenty. Use of an antidiarrheal such as diphenoxylate or an opioid for diarrhea adds thirty points. An abdominal mass contributes zero, twenty, or fifty points depending on whether it is absent, questionable, or definite. The hematocrit term compares the measured percentage with a reference of 47 for males or 42 for females, multiplying a positive deficit by six. The weight term expresses the shortfall between current and standard body weight as a percentage. This implementation does not subtract points when hematocrit exceeds the reference or current weight exceeds standard weight. The final weighted values are added and rounded to a whole-number CDAI score. Common interpretation bands define a score below 150 as clinical remission, 150 through 219 as mildly active disease, 220 through 449 as moderate to severe disease, and 450 or higher as severe or fulminant disease. Boundaries may be described slightly differently across protocols. A change of about 70 to 100 points has often been used to characterize a clinical response in research, but treatment decisions should not be based on a calculator alone. CDAI has important limitations. Several inputs are subjective, symptoms may arise from conditions other than active inflammation, and the score may not correlate closely with endoscopic healing. Modern care may also use biomarkers such as C-reactive protein or fecal calprotectin, imaging, endoscopy, patient-reported outcomes, nutrition, and complications. Ensure seven-day symptom totals are collected consistently and verify unusual results against the source data. This tool is intended for education and transparent score calculation. A clinician should interpret the result in context, particularly when symptoms worsen, weight falls, bleeding occurs, fever develops, or obstruction and abscess are possible. Severe pain, dehydration, persistent vomiting, fainting, or other urgent symptoms require prompt medical care.