How to Read a Crohn’s Colonoscopy Report (Ulcers, Strictures, “Mild/Moderate/Severe”)
Last Updated Jan 15, 2026
Colonoscopy reports can feel like a foreign language, especially when Crohn’s disease terms and severity labels are packed into a few lines. Reading the report in a step-by-step way can make it clearer what the scope actually showed, what was sampled (biopsies), and which parts still may need other tests. The goal is not self-diagnosis, but a better way to understand common Crohn’s colonoscopy report terms and prepare for a follow-up conversation.
Start with the big picture: what was examined and where Crohn’s was seen
Most Crohn’s colonoscopy findings are described by location and extent. Reports often list segments such as rectum, sigmoid, descending colon, transverse colon, ascending colon, cecum, and sometimes the terminal ileum (the last part of the small intestine). The report may also mention the ileocecal valve (the “gate” between small and large intestine), since Crohn’s commonly involves this area and it can be hard to pass through if narrowed.
Two early lines in many reports are worth slowing down for: “extent of exam” (how far the scope reached) and “quality of bowel prep” (how well the lining could be seen). If the terminal ileum was not reached or not entered, the report may say so, and that can affect how confidently the exam rules inflammation in or out in that spot.
Many reports also include whether biopsies were taken, sometimes from inflamed areas and sometimes from lining that looked normal. Biopsies are small tissue samples reviewed in a lab (pathology) to help classify inflammation and rule out other causes. Colonoscopy mainly shows the colon and the very end of the small intestine, so separate small-bowel imaging is sometimes used to evaluate areas beyond the scope’s reach. [1]
Common Crohn’s findings in plain English (ulcers, inflammation, strictures)
When a report lists ulcers, it is describing breaks in the lining. In Crohn’s, these might be described as aphthous (tiny, shallow), large, or deep/linear ulcers. Some endoscopy reports borrow structured scoring language, where ulcer size and how much surface area is involved helps summarize severity. For example, the Simple Endoscopic Score for Crohn’s Disease (SES-CD) uses ulcer size categories (none, aphthous, large, very large) and also tracks whether narrowing (stenosis) is present and whether the scope can pass through it. [2]
Reports may also use general inflammation words like erythema (redness), friability (tissue that bleeds easily), edema (swelling), or cobblestoning (a bumpy pattern). These are visual clues that the lining is irritated or inflamed, but they do not always match day-to-day symptoms.
A stricture is a narrowed section of bowel. Some strictures are related to active swelling and inflammation, and others are related to longer-term scar tissue (fibrosis). That difference matters because narrowing can behave differently over time and may be evaluated with more than one type of test, not colonoscopy alone. [3]
What “mild,” “moderate,” and “severe” usually mean, and how biopsy results fit in
Severity words in Crohn’s colonoscopy reports can be confusing because they are not always standardized. One endoscopist may write “mild” based on appearance and extent, while another may document a formal score such as SES-CD. Even when a scoring system is used, the exact cutoffs for “mild,” “moderate,” or “severe,” and what counts as “remission,” have not been fully standardized across studies and practice settings. [4]
Biopsy results often arrive after the procedure, so the colonoscopy note and the pathology report may be separate. Pathology commonly comments on patterns like “active inflammation” (ongoing irritation) and “chronic inflammation” (longer-term changes), and sometimes looks for features that support Crohn’s versus other causes. Timing varies, but many centers report biopsy results in about 1 to 2 weeks. [5]
For follow-up, it can help to bring a short checklist to the next visit:
- Which bowel segments were involved, including the terminal ileum and ileocecal valve?
- Were there ulcers, and how deep or extensive were they described?
- Was any narrowing seen, and could the scope pass?
- What did biopsies show, and were any results unexpected?
- If symptoms and scope findings do not match, what other testing (like imaging) might be used to fill in gaps?