What Your Crohn's or UC Colonoscopy Score Means

After a colonoscopy, your report often arrives filled with severity language and numbers that no one fully explained in the room. You might see a Mayo subscore, a UCEIS value, an SES-CD total, or a Rutgeerts grade, along with words like "moderate" or "mucosal healing." These endoscopic severity scores are how gastroenterologists turn what they see through the scope into a standardized number that can be compared over time. This guide explains what the common colonoscopy score for ulcerative colitis and Crohn's disease means, how each scale is built, and how the number connects to your symptoms and your lab results.

Why your colonoscopy report uses a score

A colonoscopy lets your doctor look directly at the lining of the colon and, in Crohn's disease, sometimes the end of the small intestine. The Crohn's & Colitis Foundation explains that endoscopy with biopsy lets physicians see inflammation, judge its location and severity, and take tissue samples that confirm the diagnosis and track whether treatment is working. The National Institute of Diabetes and Digestive and Kidney Diseases describes colonoscopy as a core test for confirming ulcerative colitis, judging how severe it is, and identifying which parts of the large intestine are affected. A written description alone can be subjective, so scoring systems assign points to specific findings such as bleeding, loss of the normal blood vessel pattern, and ulcers. The resulting number makes it easier to compare one scope to the next and to decide whether therapy should change.

The Mayo endoscopic subscore for ulcerative colitis

For ulcerative colitis, the most widely used colonoscopy score is the Mayo endoscopic subscore. It runs from 0 to 3, where 0 is normal or inactive disease, 1 is mild with redness and reduced blood vessel markings, 2 is moderate with marked redness and erosions, and 3 is severe with spontaneous bleeding and ulceration. This subscore is one part of the full Mayo score. The complete Mayo score combines stool frequency, rectal bleeding, the physician's global assessment, and the endoscopy finding, each rated 0 to 3, for a total of 0 to 12, with clinical remission commonly defined as a score of 2 or lower. When you see the term "mucosal healing" on your report, it usually means the endoscopic subscore fell to 0 or 1, which is a common goal of treatment. That is why the Mayo score meaning matters more than any single visit in isolation.

UCEIS: a more detailed ulcerative colitis score

The Ulcerative Colitis Endoscopic Index of Severity, abbreviated UCEIS, is a newer scale that breaks the picture into parts. It scores three findings: the vascular pattern from 0 to 2, bleeding from 0 to 3, and erosions and ulcers from 0 to 3, which are added for a total ranging from 0 to 8, with higher numbers indicating more severe inflammation. Because it separates these features, the UCEIS can capture change that a single global impression might miss, and it is often used in clinical trials and increasingly in everyday practice. If your ulcerative colitis colonoscopy results include a UCEIS value, a low number near 0 points toward healed or nearly healed lining, while a value of 4 or more generally reflects active disease that may prompt a treatment discussion. Seeing both a Mayo subscore and a UCEIS on the same report is normal, since they measure overlapping features in different ways.

SES-CD: the Crohn's disease colonoscopy score

Crohn's disease is scored differently because it can affect several separate segments of the bowel. The Simple Endoscopic Score for Crohn's Disease, abbreviated SES-CD, is the standard, and it helps get Crohn's colonoscopy results explained in consistent terms. It rates four features in each of five bowel segments: the size of ulcers, the proportion of surface that is ulcerated, the proportion of surface that is inflamed, and the presence of narrowing. Using common cutoffs, a total of 0 to 2 reflects inactive disease or endoscopic remission, 3 to 6 is mild, 7 to 15 is moderate, and 16 or higher is severe, with totals in practice reaching well above 30. Because the score adds findings across multiple segments, a person with patchy disease in more than one area can carry a higher total even when each individual spot looks limited. That is a key reason Crohn's colonoscopy results are best read segment by segment rather than as a single label.

The Rutgeerts score after Crohn's surgery

If you have had surgery to remove a diseased section of intestine, your follow-up colonoscopy may use the Rutgeerts score to look for early Crohn's recurrence at the surgical join. The scale runs from i0 to i4: i0 means no lesions, i1 means five or fewer small aphthous ulcers, i2 means more than five aphthous lesions or larger lesions with a passable narrowing, i3 means diffuse inflammation, and i4 means diffuse inflammation with deep ulcers. Grades of i0 and i1 are associated with a lower chance of the disease returning soon, while i2 and above signal endoscopic recurrence that often precedes returning symptoms. This is why many gastroenterologists schedule a scope within the first year after an intestinal resection even when a person feels well.

How your score fits with symptoms and biomarkers

A colonoscopy score is one of three signals your care team watches, alongside symptoms and blood or stool markers. The American Gastroenterological Association notes that a fecal calprotectin below 150 micrograms per gram together with a normal C-reactive protein suggests absent inflammation, and it recommends combining these biomarkers with symptoms rather than relying on symptoms alone. The same approach applies in Crohn's disease, where the association uses a fecal calprotectin under 150 micrograms per gram and a C-reactive protein under 5 milligrams per liter as thresholds and, after surgery, a stricter calprotectin under 50. Symptoms and scores do not always agree. You can feel well while a scope still shows inflammation, or feel unwell when the lining looks healed. Under the STRIDE-II international targets, clinical response is a short-term goal, normalization of laboratory markers is an intermediate goal, and improvement in endoscopic findings is the long-term target. Reading your colonoscopy score next to your calprotectin, your C-reactive protein, and how you actually feel gives a fuller picture than any single number. Keeping each scope result recorded so it can be compared with the last turns a one-time report into a trend you and your gastroenterologist can act on.