Small Bowel Crohn’s: Symptoms, Tests, and What “Ileitis” Means
Last Updated Jan 15, 2026
Seeing “ileitis” or “terminal ileitis” on a scan or colonoscopy report can feel alarming, especially for people living with Crohn’s disease. These terms describe where inflammation is happening, not always why it is happening. Understanding the meaning, common small-bowel Crohn’s symptoms, and the most-used tests (like magnetic resonance enterography and capsule endoscopy) can make the next steps feel clearer.
What “ileitis” means (and why the cause matters)
Ileitis means inflammation in the ileum, which is the last part of the small intestine. Because Crohn’s disease often affects the area where the small and large intestines meet, Crohn’s in the ileum is commonly called ileitis (sometimes “Crohn’s ileitis”). In other words, “ileitis Crohn’s” usually describes a location pattern that is common in Crohn’s, rather than a separate diagnosis. [1]
Terminal ileitis meaning: the inflammation is in the terminal ileum, which is the final segment of the ileum right before the colon. That location can help explain symptoms like right lower quadrant pain Crohn’s, since the terminal ileum sits on the lower right side of the abdomen.
It also helps to know that ileitis vs infection is a real question. Ileitis can happen for reasons other than Crohn’s, including infections, medication-related irritation (such as nonsteroidal anti-inflammatory drugs, also called NSAIDs), reduced blood flow (ischemia), and some immune-related conditions. Some bacterial ileitis can be more sudden and short-lived, often with right lower abdominal pain and diarrhea, which is one reason clinicians often look at the whole story (symptoms, timing, labs, imaging, and biopsies) before labeling ileitis as Crohn’s. [2]
Small-bowel Crohn’s symptoms and the tests commonly used (MRE, CTE, capsule)
Small bowel Crohn’s symptoms can vary widely. Common Crohn’s symptoms include diarrhea, belly cramping or pain, and weight loss. Symptoms can come and go, and they do not always match the amount of inflammation seen on tests. [3]
Because there is no single test that confirms Crohn’s disease in every case, care teams often combine several tools. Many people are evaluated with colonoscopy, which can examine the colon and often the very end of the ileum, and it can include biopsies (small tissue samples). Imaging may include computed tomography (CT) enterography (CTE) or magnetic resonance (MR) enterography (MRE), which are designed to get a clearer look at the small bowel. Capsule endoscopy (swallowing a small camera) may also be used to look for small-bowel inflammation, but clinicians are careful when narrowing (a stricture) or blockage is suspected because the capsule can get stuck. [4]
For people comparing MRE ileitis testing with other options, MRE is often valued because it creates detailed small-intestine images without ionizing radiation, which can matter when repeat imaging is needed over time. Like most enterography studies, it typically uses oral contrast (and sometimes intravenous contrast) to highlight the bowel. [5]
Helpful questions for a gastroenterology visit after a “terminal ileitis” result include:
- What is the suspected cause (Crohn’s flare, infection, medication effect, something else)?
- Which tests best clarify location and severity (colonoscopy, MRE/CTE, capsule)?
- Are there signs of narrowing, abscess, or other complications that change test choice?