The interplay between inflammatory bowel disease (IBD) and primary sclerosing cholangitis (PSC) has intrigued gastroenterologists and hepatologists for decades.

Ulcerative colitis (UC), the most frequent IBD phenotype associated with PSC, coexists in up to 80% of PSC patients, while 2–7% of UC patients develop PSC.

This overlap gives rise to a distinct condition - PSC-IBD - marked by atypical disease behaviour, heightened cancer risk, and unique surgical challenges.

A recent review by Professor Shen and colleagues published in eGastroenterology examines how colectomy and liver transplantation, two key surgical interventions, alter the course of both diseases.

The findings highlight nuanced risks, uncertain benefits, and clinical dilemmas that demand careful navigation.

PSC's impact on IBD

Patients with PSC-IBD often exhibit extensive colitis with rectal sparing and backwash ileitis, yet paradoxically milder symptoms compared with isolated UC.

Despite fewer flares, the risk of colitis-associated neoplasia (CAN) is three- to fivefold higher in PSC-UC than in UC alone.

This necessitates annual surveillance colonoscopy from the time of PSC diagnosis, regardless of disease duration.

When colectomy is required, usually for neoplasia or refractory disease, outcomes differ.

While perioperative safety of restorative proctocolectomy with ileal pouch–anal anastomosis (IPAA) is acceptable, PSC patients face higher risks of chronic pouchitis and prepouch ileitis, often refractory to standard therapies.

 Oral vancomycin has emerged as a promising option in this context, with evidence of both colonic and hepatic benefits.

IBD's impact on PSC

The influence of IBD on PSC progression is less well defined.

While medical therapy for UC has no proven impact on PSC, long-standing UC may increase the risk of PSC-associated cholangiocarcinoma (CCA).

Studies suggest colectomy does not reliably protect against PSC progression or CCA development.

Indeed, some cohorts reported a paradoxical increase in CCA risk after colectomy.

This challenges the notion that removing the colon disrupts a pathogenic gut–liver axis, reinforcing the idea that PSC pathogenesis involves more than colonic inflammation.

Genetic predisposition, immune dysregulation, and microbiome alterations likely play central roles.

The question of colectomy

For UC, proctocolectomy is curative, but its effect on PSC remains controversial.

Earlier studies suggested possible protective effects, but larger registries and meta-analyses indicate colectomy does not significantly alter PSC progression, transplant-free survival, or CCA risk.

Some evidence even suggests colectomy may increase CCA risk in PSC patients, though findings are inconsistent.

Thus, colectomy decisions in PSC-IBD are primarily driven by colonic indications—dysplasia, cancer, or refractory disease—rather than expectations of altering PSC course.

Recurrent PSC after transplantation

Recurrent PSC (rPSC) affects one-fifth of transplant recipients within a decade.

Active IBD post-transplant is a significant risk factor, strengthening the hypothesis that intestinal immune activity influences biliary injury.

While some studies suggest pre-transplant colectomy reduces rPSC risk, others show no effect once IBD activity is accounted for.

More rigorous studies are needed to clarify whether colectomy truly modifies recurrence risk.

Clinical implications

The review underscores several practical lessons for clinicians: 

1. Surveillance is paramount: PSC-IBD carries heightened risks of colorectal and biliary malignancy, warranting aggressive screening.
2. Surgery requires caution: Colectomy may relieve colonic disease but does not cure PSC; pouch outcomes are worse in PSC patients.
3. Transplant reshapes risks: liver transplantation prolongs survival but introduces risks of de novo IBD, malignancy, and recurrent PSC.
4. Tailored immunosuppression matters: Agents like tacrolimus may worsen IBD, while azathioprine may be protective.
5. Research gaps remain: The pathogenesis of PSC-IBD is incompletely understood, and current evidence is largely retrospective with small cohorts.

Conclusion

The coexistence of IBD and PSC presents a complex clinical challenge, as colectomy and liver transplantation address disease burden but do not eliminate risks of inflammation, malignancy, or recurrence.

PSC often dictates the IBD course, underscoring the need for vigilant, individualised care and future large-scale, longitudinal studies to better define management strategies.

Source: First Hospital of Jilin University