The colitis

The Distinct Colitis of IBD-PSC

The bowel inflammation in IBD-PSC often looks different from typical ulcerative colitis, and knowing the pattern changes how it is watched. It tends to be widespread yet mild and is often most active on the right side of the colon. Some studies also find the rectum spared, though others find this uncommon. 1–3,11,12

What sets this colitis apart
Extensive but often mild

The inflammation frequently involves the whole colon, yet day-to-day symptoms can be milder than expected, sometimes almost silent. 2,3

Rectal sparing & backwash ileitis

The rectum may be relatively spared (unlike most ulcerative colitis), and inflammation can extend back into the end of the small intestine. 1,3

Right-sided emphasis

When cancer risk shows up, it is more often in the right (proximal) colon, which shapes how and where surveillance biopsies are taken. 6,15

Quiet but not harmless

Even mild-seeming colitis carries an elevated cancer risk, so surveillance still applies in full, regardless of how you feel. 4,5

Cancer surveillance, the key point

IBD-PSC carries a substantially higher colorectal-cancer risk than IBD without PSC. Guidelines recommend yearly surveillance colonoscopy beginning at the time of PSC diagnosis, earlier and more often than in IBD alone. Keeping up with these scopes is the single most protective thing you can do. 4–6,14,15

Colorectal cancer

Higher risk and earlier onset, hence annual surveillance with chromoendoscopy or high-definition colonoscopy and targeted biopsies. 4,14

Bile-duct & gallbladder cancer

PSC also raises the risk of cholangiocarcinoma and gallbladder cancer; your liver team monitors these with imaging and blood tests. 16–18

Why surveillance starts at PSC diagnosis, not later Advanced

In IBD without PSC, surveillance colonoscopy usually begins about 8–10 years after diagnosis. In IBD-PSC the cancer risk is high enough, and can appear early enough, that guidelines recommend starting annual surveillance from the moment PSC is diagnosed. 4,5

Because the neoplasia tends to be right-sided and can arise in flat, hard-to-see mucosa, high-definition or dye-spray (chromoendoscopy) technique with targeted biopsies is preferred. 6,15