The exact cause of IBD is unknown, but its etiology is multifactorial, involving genetic susceptibility, environmental influences, alterations in the gut microbiome, and immune dysregulation (Zhang and Li, 2014). Genetic studies have identified numerous risk loci, while factors like smoking, diet, infections and certain medications (e.g., nonsteroidal anti-inflammatory drugs, antibiotics) can trigger or worsen disease (Liu and Stappenbeck, 2016). IBD pathogenesis is strongly influenced by gut microbiome changes, with dysbiosis and reduced diversity commonly observed (Kostic et al., 2014). Abnormal regulation of both innate and adaptive immunity sustains the ongoing inflammation (Neurath, 2019).

Diagnosing IBD requires multimodal approach, including clinical evaluation, laboratory testing, endoscopy, histology and imaging studies (Magro et al., 2017). Laboratory tests may reveal elevated inflammatory markers, such as C-reactive protein (CRP) and fecal calprotectin, while colonoscopy provides direct visualization of the mucosa and biopsy for histological confirmation (Mosli et al., 2015; Magro et al., 2017). Imaging techniques like, computed tomography enterography (CTE), magnetic resonance enterography (MRE) and magnetic resonance imaging (MRI) of the pelvis are useful in assessing disease activity and complications like strictures, fistulas, and abscesses in CD (Panes et al., 2013). IBD management focuses on inducing and maintaining remission, improving quality of life and minimize complications. Treatments include aminosalicylates, corticosteroids, immunomodulators and biologics targeting specific inflammatory pathways. The choice of treatment depends on the severity and extent of disease, prior response, and the patient’s comorbidities (Ungaro et al., 2017).

CDI in IBD arises from a complex interplay of microbiological, immunological and therapeutic factors (Ananthakrishnan, 2011; Allegretti et al., 2016). Understanding these mechanisms is crucial for enhancing prevention and management in this high-risk group (Figure 1).

Distinguishing CDI from an IBD flare is challenging because both share symptoms such as diarrhea, abdominal pain, fever and increased stool frequency. This overlap complicates diagnosis and when CDI coexists with IBD, it is associated with worse outcomes, including higher morbidity, more hospitalizations and increased surgical risk. Diarrhea is common to both; in CDI it is often watery, profuse and foul-smelling, while in IBD it varies in consistency and may contain blood or mucus (Ananthakrishnan, 2011). Abdominal pain in CDI is often diffuse, whereas in IBD it reflects inflammation sites (e.g., RLQ in Crohn’s, LLQ in UC), though both can overlap. Fever occurs with CDI as a sign of infection but may also signal severe IBD or complications like abscesses. Leukocytosis is typical of CDI (often >15,000/mm³) but also occurs in severe IBD, limiting diagnostic value. Urgency and tenesmus are hallmarks of UC but may also appear in CDI due to toxin-induced colonic inflammation. Finally, fatigue and malaise, secondary to inflammation, electrolyte loss or anemia, are nonspecific and common to both conditions (Alhobayb and Ciorba, 2023). This overlap leads to underdiagnosis, allowing CDI to progress to severe complications such as toxic megacolon, perforation or sepsis. The challenge is compounded in IBD patients on immunosuppressive therapy, as agents like corticosteroids and biologics can dull the inflammatory response, producing atypical or milder CDI symptoms that mimic a flare and further delay recognition (Goodhand et al., 2011; Khanna and Pardi, 2012).

Misdiagnosing CDI as an IBD flare can lead to inappropriate use of corticosteroids or immunosuppressants, worsening infection, while mistaking a flare for CDI and using antibiotics may aggravate dysbiosis and IBD activity (Ananthakrishnan, 2011; Goodhand et al., 2011). Such errors, along with diagnostic delays, increase morbidity and mortality, with CDI in IBD patients linked to longer hospital stays, more surgeries, and higher death rates. Accurate distinction requires a comprehensive workup, including stool toxin or PCR testing and, in some cases, endoscopy or imaging, especially when symptoms overlap or responses to standard therapy are poor (Surawicz et al., 2013; Khanna and Pardi, 2014).

Timely diagnosis of CDI in IBD is essential but difficult because its symptoms closely resemble IBD flares. Current diagnostic tools, including stool assays, cultures, PCR, toxin tests, and radiologic or endoscopic evaluations, each have limitations in accuracy, speed, and applicability in IBD, making differentiation challenging.

Managing CDI in IBD patients is challenging due to overlapping symptoms and the heightened risk of morbidity and mortality when both conditions coexist. Standard CDI therapies include antibiotics and fecal microbiota transplantation (FMT), which aim to eradicate C. difficile and restore microbial balance. In IBD patients, however, these treatments require special consideration given their underlying disease activity and concurrent immunosuppressive therapies. This section reviews the mechanisms, effectiveness, and special considerations for applying standard CDI treatments in IBD patients (Crobach et al., 2016; Guh and Kutty, 2018).

Antibiotic therapy remains the cornerstone of CDI management, with treatment choices guided by disease severity, prior therapies and comorbidities such as IBD. The main antibiotics are metronidazole, vancomycin, and fidaxomicin (Cornely et al., 2012; McDonald et al., 2018). Metronidazole was once a first-line therapy for mild CDI but is now discouraged as primary treatment due to lower efficacy versus vancomycin or fidaxomicin, especially in severe or recurrent cases. It inhibits DNA synthesis in anaerobes but achieves lower colonic concentrations. In IBD patients, altered microbiota and reduced absorption can further limit effectiveness, while side effects such as neuropathy or GI intolerance may add risk. Nowadays, metronidazole is largely reserved for mild cases when cost or access limits preferred treatments, or occasionally in combination therapy, though evidence is limited (Khanna et al., 2015; Tamma et al., 2019). Vancomycin is now the preferred first-line treatment mild to severe CDI, given orally to deliver high colonic concentrations with minimal systemic absorption. It inhibits bacterial cell wall synthesis and is highly effective, including in IBD patients, where it shows higher cure rates and fewer recurrences compared to metronidazole (Cornely et al., 2012; McDonald et al., 2018). Standard dosing is 125 mg orally four times daily for 10 days, with higher doses used in severe cases. Recurrent or severe IBD cases may require prolonged or repeated courses, but monitoring is essential to minimize resistance risk (Debast et al., 2014). Fidaxomicin is a newer macrocyclic antibiotic with cure rates at least comparable to vancomycin and a significantly lower recurrence rates (Louie et al., 2011; Cornely et al., 2012). It inhibits bacterial RNA synthesis and due to its narrow spectrum against C. difficile, preserves normal gut microbiota, which is an important advantage for IBD patients at high risk of relapse. Clinical data support its use in recurrent CDI, with reduced disruption of gut flora aiding IBD stability. The standard regimen is 200 mg twice daily for 10 days. Its major limitation remains cost, though guidelines increasingly recommend it for IBD patients with frequent relapses (Khanna et al., 2015; Guh and Kutty, 2018).

FMT involves transferring stool from a healthy donor to restore gut microbial balance in patients with recurrent CDI. It is highly effective, with cure rates exceeding 80-90% especially when standard antibiotics fail (van Nood et al., 2013; Kelly et al., 2014). FMT restores colonization resistance by reintroducing a diverse microbiome that outcompetes C. difficile and supports gut health. Delivery routes include colonoscopy, nasogastric or nasojejunal tube, enema or oral capsules (Cammarota et al., 2015; Allegretti et al., 2020). In IBD patients, FMT demonstrates high efficacy for treating CDI but raises unique considerations assome patients experience IBD flares post-FMT, whereas others maintain or even improve disease stability (Cammarota et al., 2015; Allegretti et al., 2020). MT is reserved for IBD patients with multiple CDI recurrences unresponsive to antibiotics, though it is being considered earlier in difficult cases given their higher recurrence risk (Kao et al., 2017; Quraishi et al., 2017). Colonoscopy allows targeted delivery but carries higher procedural risks in severe colitis. Less invasive methods, such as capsules or enemas, are safer alternatives though efficacy may vary (Costello et al., 2019; Allegretti et al., 2020).

Many IBD patients receive immunosuppressants, such as corticosteroids, thiopurines, or biologics, which increase the risk of severe or recurrent CDI and complicate antibiotic selection. Close coordination between gastroenterology and infectious disease specialists is essential to balance efficacy and safety (Kelly et al., 2014; Khanna et al., 2015). Both antibiotics and FMT may trigger IBD flares as Antibiotics can disrupt the gut microbiota, while FMT, may provoke an immune response that worsens IBD. Hence, Careful monitoring and individualized therapy are necessary to minimize these risks (Allegretti et al., 2016; Saha et al., 2021). As IBD patients are highly susceptible to recurrent CDI, a proactive treatment strategy is needed. Fidaxomicin is often preferred for its lower recurrence rates, while FMT is considered in patients with multiple relapses to prevent further episodes and reduce disease burden (Cornely et al., 2012; Louie et al., 2011).

Immunosuppressive and biologic therapies are central to IBD management but complicate CDI treatment by altering immune responses and gut microbiota. Management requires balancing infection eradication with inflammation control (Kelly et al., 2014; Khanna et al., 2015). Corticosteroids agents like prednisone and budesonide are widely used for flares but impair host defenses and worsen CDI outcomes. When CDI is diagnosed, tapering or reducing steroids is generally advised to lower the risk of severe or recurrent infection. If tapering threatens IBD stability, the lowest effective dose should be used, with consideration of alternatives such as biologics or cyclosporine (Allegretti et al., 2016; Saha et al., 2021). Immunomodulator drugs (azathioprine, methotrexate, thiopurines) maintain remission but increase susceptibility to infections. In mild CDI, they may be continued with close monitoring. In severe or fulminant disease, temporary discontinuation may help clear the infection, although the risk of flare must be weighed carefully. Individualized decisions and coordination between gastroenterology and infectious disease specialists are essential (Khanna and Pardi, 2012; Allegretti et al., 2016).

Biologic Agents (anti-TNF, integrin inhibitors, IL-12/23 inhibitors) are highly effective for moderate to severe IBD, biologics also raise CDI risks. In mild CDI with stable patients, biologics can often be continued while treating the infection. However, in severe CDI sepsis, therapy should be paused until stabilization. Switching to agents with gut-selective activity, such as vedolizumab may reduce systemic immunosuppression while maintaining IBD control (Kelly et al., 2014; Khanna et al., 2015; Saha et al., 2021).

Recurrent CDI is common in IBD patients, affecting up to 30% after initial treatment and more in those with multiple prior recurrences. Management requires a proactive, individualized approach that accounts for their higher recurrence risk and underlying disease (Cammarota et al., 2015; Allegretti et al., 2016). Extended or pulse regimens of vancomycin or fidaxomicin are frequently used to reduce relapse. These schedules gradually decrease C. difficile burden while supporting microbiota recovery, which is vital for restoring colonization resistance (Kelly et al., 2014). Owing to its narrow spectrum and reduced effect on commensal flora, fidaxomicin is increasingly favored for recurrent CDI. For IBD patients, who are particularly prone to relapse or flares from broad-spectrum agents, fidaxomicin is often the optimal choice, especially in those with multiple recurrences (Louie et al., 2011; Cornely et al., 2012; Allegretti et al., 2016).

FMT is highly effective for recurrent CDI after antibiotic failure, achieving cure rates exceeding 80–90% in most studies. Restoring microbial diversity strengthens colonization resistance against C. difficile. In IBD patients, however, FMT requires consideration; while many respond well, some experience disease exacerbations (Cammarota et al., 2015; Allegretti et al., 2016). FMT is generally reserved for IBD patients with multiple CDI recurrences who do not respond to antibiotics. Delivery routes include colonoscopy, oral capsules, or enemas, with the choice based on severity and safety considerations. Colonoscopic delivery allows targeted placement but carries procedural risks, especially in severe colitis. Given potential flare risk, FMT should be performed in experienced centers, with individualized planning and post-procedure monitoring (Kelly et al., 2014; Allegretti et al., 2016; Saha et al., 2021).

Surgical intervention may be required in IBD patients with severe or fulminant CDI who fail medical therapy or develop life-threatening complications such as toxic megacolon, perforation, or refractory colitis (Hall and Mah, 2017; Barkun et al., 2019). Surgery is reserved for patients who do not improve with optimized medical management, including high-dose antibiotics and supportive care. Common triggers include clinical deterioration, toxic megacolon, perforation, severe bleeding, or drug-refractory colitis. Subtotal or total colectomy is the standard, often lifesaving in fulminant colitis with perforation, peritonitis, or sepsis. In selected cases, a diverting loop ileostomy with colonic lavage may be considered as a less invasive alternative, offering colonic preservation while reducing toxins, though suitability depends on disease extent and patient stability (Siddiqui and Young, 2020). Outcomes in IBD patients are often complicated by malnutrition, immunosuppression, and comorbidities. Surgical decisions should be made within a multidisciplinary team, including gastroenterologists, surgeons, and infectious disease specialists, to optimize preoperative care and improve prognosis (Steele et al., 2015).

Diagnostic guidelines, both the IDSA and ACG guidelines endorse a stepwise diagnostic approach for Clostridioides difficile infection, in which nucleic acid amplification testing or glutamate dehydrogenase screening is used initially, followed by toxin enzyme immunoassay to confirm active toxin production. The ACG further recommends repeat testing in patients with negative initial results when clinical suspicion remains high.

The guidelines from the Infectious Diseases Society of America (IDSA) and the Society for Healthcare Epidemiology of America (SHEA) guidelines recommend oral vancomycin (125 mg four times daily for 10 days) as first-line therapy for mild to non-fulminant CDI, while fulminant disease is treated with high-dose oral vancomycin (500 mg four times daily) plus intravenous metronidazole, with adjunctive rectal vancomycin in cases of severe ileus. For a first recurrence, a pulsed–tapered vancomycin regimen is advised. Despite therapy, approximately 25% of patients relapse; however, prolonged vancomycin courses (21–42 days) significantly reduce recurrence compared with shorter regimens (10–14 days). For recurrent CDI, the 2017 IDSA guidelines recommend rifaximin (400 mg three times daily for 20 days) following a 10-day course of vancomycin, in addition to tapering or pulse regimens with vancomycin. The rifaximin “chaser” strategy has shown promise in reducing recurrence and is included in current IDSA guidance for second or subsequent CDI episodes.

The 2019 British Society of Gastroenterology guidelines for IBD state that discontinuation of corticosteroid therapy during treatment for CDI is not required in patients with acute severe UC. Probiotics are not recommended for the prevention of CDI, and the American College of Gastroenterology guidelines explicitly advise against their use for CDI prophylaxis. The 2021 European Crohn’s and Colitis Organization (ECCO) guidelines on IBD management indicate that the impact of immunosuppressive therapies on the course and progression of CDI in patients with IBD remains uncertain. The 2018 guidelines jointly issued by the British Society of Gastroenterology and the Healthcare Infection Society recommend the use of FMT for patients with recurrent CDI who have experienced at least two recurrences, as well as for those with a single recurrence who are considered at high risk for subsequent episodes, including individuals with severe or complicated CDI.

The severity of IBD and the presence of flares strongly influence the management of CDI. Treatment is complicated by active intestinal inflammation, the immunosuppressive therapies often required for IBD, and the disrupted gut microbiota that increases susceptibility to CDI. Disease severity and flare activity can affect diagnosis, therapeutic response and overall prognosis in this high-risk population (Khanna and Pardi, 2012). Severe IBD flares share symptoms with CDI, such as diarrhea, abdominal pain, rectal bleeding, fever, and leukocytosis, making clinical distinction difficult. This overlap can delay diagnosis, lead to inappropriate therapy, or postpone CDI-specific treatment and worsen outcomes. Active colitis with compromised mucosa may further mask or mimic CDI, which may complicate the diagnostic process (Khanna and Pardi, 2012). Patients with severe IBD or active flares are more prone to fulminant CDI due to disrupted mucosa, loss of protective gut flora, and immune dysregulation that limits effective response to infection. These patients face higher risks of serious complications requiring prompt, aggressive and often multidisciplinary management (Martínez-Lozano et al., 2025). Managing CDI in IBD patients is complicated by inflammation-driven changes in absorption, motility and pharmacokinetics. During severe flares, oral antibiotics like vancomycin may achieve unpredictable or subtherapeutic levels due to mucosal damage, sometimes requiring higher or adjusted dosing. Patients are also more prone to antibiotic-related side effects, including GI intolerance and secondary infections, further complicating therapy (Debast et al., 2014). Recurrence is more frequent in IBD, affecting up to 40–60% of patients with severe or extensive disease, leading to greater morbidity and healthcare burden. Extended or pulsed regimens of fidaxomicin or vancomycin may also help suppress C. difficile while allowing gradual microbiome recovery (Cornely et al., 2012). FMT is highly effective in the general population (80-90% cure rates), but outcomes in IBD are less predictable. Thus, FMT should be reserved for carefully selected IBD patients, with pre-procedure optimization and close follow-up (Quraishi et al., 2017).

IBD patients often require immunosupression but this can hinder C. difficile clearance and increase recurrence risk (Khanna and Pardi, 2012; Torres et al., 2020). In mild CDI, immunosuppressive therapy may be continued with close monitoring. For severe disease, tapering or temporarily discontinuing agents is often necessary, particularly corticosteroids, which are linked to poorer outcomes. Biologics are usually withheld until infection control is achieved (Navaneethan et al., 2010). Gut-selective therapies like vedolizumab may be considered in high-risk patients, as they offer effective IBD control with less systemic immunosuppression (Feagan et al., 2013).

IBD patients with severe disease are highly vulnerable to CDI complications. Which can progress rapidly and require close monitoring (Debast et al., 2014). Optimal management often involves a team of gastroenterologists, infectious disease specialists and surgeons to coordinate therapy, track complications and determine the need for surgery (Torres et al., 2020). Early surgical consultation is considered in severe and complicated CDI cases to allow timely, life-saving intervention (Siddiqui and Young, 2020).

Managing CDI in IBD patients is complicated by potential drug–drug interactions (DDIs) between the different classes of medications that can affect both efficacy and safety (Khanna and Pardi, 2012). Combining antibiotics, immunosuppressants, biologics and supportive therapies may alter drug absorption and metabolism, increasing the risk of adverse events and complicating treatment. Recognizing and managing these interactions is essential for optimizing outcomes, preventing complications and ensuring patient safety during complex therapy regimens (Debast et al., 2014; Torres et al., 2020; Khanna and Pardi, 2012). Some common drug–drug interactions in CDI and IBD management are listed in Table 1, along with their mechanisms and clinical relevance.

Oral vancomycin, a first-line CDI antibiotic, is minimally absorbed systemically, limiting most drug interactions. However, in severe IBD with a compromised gut barrier, absorption can increase, rarely leading to systemic exposure and potential additive toxicity when combined with immunosuppressants like azathioprine or methotrexate, especially in patients with renal impairment or bone marrow suppression risk. While direct interactions with corticosteroids are minimal, high-dose steroids with vancomycin may heighten risks of GI bleeding, delayed healing, or reduced CDI treatment response due to immunosuppression (Lei et al., 2019). Fidaxomicin, also minimally absorbed, offers a lower recurrence rate for CDI and less disruption of gut flora. No direct pharmacokinetic interactions exist between biologics (e.g., anti-TNF agents), but combined immune modulation can influence the risk of infection and the course of IBD. Anti-TNF drugs may increase susceptibility to infections, while fidaxomicin could indirectly affect IBD activity by altering the microbiota (Figure 2).

Vedolizumab, with its gut-specific action, offers less systemic immunosuppression and is considered safer in IBD patients at high CDI risk. Clinicians should closely monitor for infection or IBD flares and adjust immunosuppressive regimens as needed during CDI therapy (Cornely et al., 2012).

Corticosteroids, frequently used in IBD flares, can interact with metronidazole, a treatment for CDI, by affecting cytochrome P450 enzymes that metabolize metronidazole. This interaction may alter drug levels, leading to reduced efficacy or increased risk of toxicity, including neurotoxicity (peripheral neuropathy), especially with long-term corticosteroid use. Patients receiving both should be monitored for neurological symptoms (Hutson et al., 2013; Debast et al., 2014). Another immunosuppressant, Thiopurines (azathioprine, 6-mercaptopurine) are common immunosuppressants for IBD, metabolized via the thiopurine methyltransferase (TPMT) pathway. Some antibiotics, notably allopurinol, although not used for CDI treatment, can interact with thiopurines, heightening bone marrow suppression risk. While metronidazole does not directly interact, combining it with other drugs like allopurinol increases the chance of myelosuppression from toxic metabolic accumulation. Co-administration in polypharmacy situations requires caution (Lim and Chua, 2018). Also both thiopurines and metronidazole can contribute to bone marrow suppression, especially in patients with liver dysfunction or multiple immunosuppressants. Regular complete blood count (CBC) monitoring is essential, and any sign of cytopenia should prompt a review and possible adjustment of concurrent therapies to minimize hematologic risk (Debast et al., 2014).

Proton pump inhibitors (PPIs) used for gastroesophageal reflux disease (GERD) or gastritis in IBD, can raise CDI risk by suppressing gastric acid, weakening the natural defense against pathogens. When combined with CDI antibiotics, such as vancomycin or fidaxomicin, PPIs may further promote C. difficile persistence, potentially reducing treatment efficacy. Clinicians should routinely reassess the need for PPIs and consider deprescribing or using the lowest effective dose to minimize the risk (Deshpande et al., 2012; Janarthanan et al., 2012). Probiotics are sometimes added to lessen antibiotic-associated diarrhea or CDI, but their role in IBD is controversial. There are apprehensions that some strains may unpredictably alter the gut microbiome, with possible effects on IBD activity and antibiotic effectiveness. For IBD patients with mild disease and no immunosuppression, certain probiotics, such as Saccharomyces boulardii, may be beneficial. However, in those with severe disease or on immunosuppressants, probiotics carry a risk of serious infections (e.g., fungemia) and should be used cautiously or avoided (Klarin et al., 2008).

Inflammatory changes, strictures, or past surgeries commonly alter gut absorption in IBD patients. Antibiotics like vancomycin and fidaxomicin, which work locally in the colon, maybe less effective during severe flares due to rapid transit and reduced mucosal area (Khanna and Pardi, 2012). Ongoing inflammation and damage in severe IBD may cause malabsorption, requiring higher or more frequent doses of CDI antibiotics to maintain effective colonic concentrations (Debast et al., 2014). Dosing should be adjusted based on IBD severity and clinical response. Extended regimens, higher doses, or alternative delivery methods such as rectal vancomycin enemas may be needed for optimal treatment (Cornely et al., 2012).

CDI in IBD patients poses challenges due to antibiotic resistance and treatment failures. Frequent antibiotic use and immunosuppressive therapies increase the complexity of CDI management. Resistance to standard treatments, recurrent infections, and failures significantly impact outcomes (Markantonis et al., 2024).

Effective management of treatment failures in IBD patients with CDI requires addressing both infection and underlying IBD. Optimization of antibiotic therapy is crucial. Using combination therapy (e.g., oral vancomycin plus IV metronidazole) in severe cases may be necessary. Higher or extended dosing can help achieve therapeutic levels in patients with severe colonic inflammation or altered absorption (Cornely et al., 2012). Fidaxomicin use can be beneficial in recurrent CDI due to its narrow spectrum and minimal microbiota disruption (Louie et al., 2011). FMT may restore gut flora and may be effective for recurrent CDI after multiple antibiotic failures. In IBD, FMT carries flare risk and requires careful monitoring (Paramsothy et al., 2017; Quraishi et al., 2017). Monoclonal antibodies like bezlotoxumab targeting C. difficile TcdB can reduce recurrence, especially in high-risk IBD patients (Wilcox et al., 2017). Optimizing IBD treatment is crucial to decrease CDI recurrence. Modifying immunosuppressants or biologics and balancing inflammation control without excessive immunosuppression is essential (Ananthakrishnan et al., 2013). Minimizing unnecessary antibiotics through stewardship and alternative IBD management helps prevent resistance and treatment failures (Slimings and Riley, 2014). The various therapeutic strategies for CDI treatment and their stage of study have been discussed in Table 2.

Antimicrobial stewardship involves coordinated strategies to optimize antibiotic use, aiming to treat infections effectively while minimizing harms like resistance, toxicity and gut microbiota disruption. In IBD patients, stewardship is especially important because frequent antibiotic use for infections or complications increases their risk of CDI and recurrence (Slimings and Riley, 2014). Applying stewardship principles helps reduce CDI incidence, improve outcomes and preserve antibiotic effectiveness. This section outlines the key goals and strategies of antimicrobial stewardship tailored to IBD patients at risk for CDI. The primary goal of antimicrobial stewardship in IBD patients is to optimize antibiotic use for the best outcomes while minimizing the risks from inappropriate or excessive exposure. Key principles include appropriately choosing antibiotics. Choosing targeted agents based on infection type, patient factors, local resistance, and microbiota impact, favoring narrow-spectrum antibiotics to preserve gut flora and reduce CDI risk (Crobach et al., 2016). Tailoring dose and length to maximize efficacy and limit adverse effects or resistance, considering altered pharmacokinetics, prior antibiotic use, and CDI risk in IBD. It is necessary to restrict antibiotics to clear bacterial infections, avoiding them for viral illnesses, mild IBD flares or uncomplicated conditions where benefits are unclear (Davey et al., 2017). Continuous monitoring of reassessing therapy, using culture data and patient response to guide narrowing or stopping antibiotics to reduce unnecessary exposure (Baur et al., 2017).

Effective antimicrobial stewardship in IBD patients at risk for CDI involves multiple strategies, including the development of evidence-based, locally tailored protocols for antibiotic use in IBD, including standardized approaches to diagnosis, treatment choice, and duration (Slimings and Riley, 2014). Providing targeted recommendations for common IBD infections (e.g., perianal abscess, pouchitis), favoring appropriate agents like short-course metronidazole and ciprofloxacin, and avoiding high-risk antibiotics for non-specific symptoms (Slimings and Riley, 2014). Regularly auditing antibiotic prescribing patterns to detect inappropriate use and provide prescribers with feedback and education on stewardship principles and CDI risk reduction (Davey et al., 2017). Promoting the use of narrow-spectrum antibiotics when possible to preserve gut microbiota and reduce CDI risk. Encourage alternatives to high-risk drugs like clindamycin and fluoroquinolones, substituting safer options such as doxycycline when appropriate (Czepiel et al., 2019). Preferring shorter antibiotic courses (e.g., 5–7 days) has been shown to be equally effective and less likely to cause CDI; individualize duration based on clinical response and reassess need frequently (Spellberg and Rice, 2019). Limiting C. difficile testing to clinically warranted cases, avoiding routine screening that may detect asymptomatic colonization. Employ rapid diagnostics (e.g., PCR) alongside clinical assessment to guide appropriate therapy, preventing overtreatment (Crobach et al., 2016). Implementing antimicrobial stewardship in IBD patients offers several benefits including reduced incidence of CDI. Optimizing antibiotic use reduces exposure to high-risk agents, such as fluoroquinolones and clindamycin, thereby preserving gut microbiota and decreasing the risk of CDI (Baur et al., 2017). The appropriate antibiotic use reduces CDI complications, such as toxic megacolon, sepsis, and colectomy, while minimizing adverse drug reactions and enhancing the quality of life (Reznik et al., 2025). Stewardship slows resistance development by promoting judicious use of antibiotics, critical for IBD patients frequently receiving multiple antibiotic courses (Davey et al., 2017). By preventing unnecessary antibiotic use and CDI-related complications, stewardship programs reduce hospitalizations, extended treatments and surgical costs, easing healthcare financial burdens (Baur et al., 2017). While antimicrobial stewardship is beneficial, its use in IBD patients faces challenges such as frequent hospitalizations and infections require careful balancing of necessary antibiotic use with stewardship principles, which is especially tough in severe cases (Slimings and Riley, 2014). IBD flares and infections share symptoms, making it hard to know when antibiotics are needed and increasing the risk of overuse. Patients and providers may resist limiting antibiotics due to safety concerns, so education is crucial. Effective programs demand staff, diagnostics, and time, which may be lacking in smaller or outpatient settings.

Probiotics and prebiotics are being explored as adjuncts to prevent and manage CDI in IBD patients, who are at increased risk due to disrupted gut microbiota, frequent antibiotic use and immunosuppression. They aim to restore healthy microbiota and improve resistance to C. difficile, but their effectiveness and safety, especially in IBD, are still debated and complex (Singh et al., 2025).

Vaccination presents a promising approach for CDI prevention, especially in high-risk groups like IBD patients. Current vaccines target C. difficile toxins, TcdA and TcdB to generate neutralizing antibodies, aiming to prevent or lessen disease severity. Toxoid-based vaccines utilize inactivated toxins, demonstrating a strong immune response in early trials; however, their effectiveness in IBD patients, who often have altered immunity, remains unclear. Several candidates, including Pfizer’s PF-06425090, are in advanced clinical trials assessing prevention of primary and recurrent CDI. Challenges specific to IBD patients include immunosuppressive therapy potentially reducing vaccine efficacy, safety concerns regarding IBD symptom exacerbation, and unknown long-term immunity duration. Further research is needed to determine the optimal vaccination timing, safety, and whether booster doses are necessary to maintain protection in this population. Despite setbacks in meeting primary endpoints, ongoing vaccine development continues to offer hope for the prevention of CDI in vulnerable groups (Wilcox, 2012).

The gut microbiome is vital for intestinal health and protection against CDI. In IBD patients, dysbiosis, an imbalance in gut microbiota, raises CDI risk. Microbiome modulation aims to restore a healthy microbial community that resists colonization by C. difficile. Emerging therapies include live biotherapeutics using beneficial bacterial strains like Faecalibacterium prausnitzii and Akkermansia muciniphilia, which show anti-inflammatory effects and support the gut barrier. Clinical trials are evaluating their safety and efficacy in IBD patients (Buffie et al., 2014). Bacteriophage therapy employ viruses that specifically target and kill C. difficile without harming beneficial microbes. This approach, alone or with antibiotics, has shown promise in animal studies, with human trials planned (Khanna et al., 2016). Additionally, microbiota-based drugs such as defined microbial consortia offer a controlled alternative to FMT. These combinations of live microbes aim to restore gut balance and prevent CDI more predictably than FMT, which can have variable effects. Together, these innovative strategies hold potential to improve CDI prevention and gut health in IBD patients by targeting microbial imbalances and enhancing colonization resistance.

Early, accurate diagnosis of CDI in IBD patients is essential to prevent severe disease and transmission. Current tests like stool toxin assays and molecular methods face challenges due to IBD symptoms overlap. Advances include NGS, which profiles gut microbiome changes preceding infection, enabling earlier intervention. Rapid POC tests detecting C. difficile toxins provide quick and sensitive bedside diagnosis, crucial for timely management of IBD patients. Biomarker-based assays aimed at differentiating CDI from IBD flares utilize host immune markers, metabolites, or microbial components. Combining these biomarkers could enhance diagnostic accuracy and inform treatment decisions. Together, these emerging technologies promise faster, more precise CDI detection in IBD, improving patient outcomes by enabling tailored therapies and reducing misdiagnosis (Polage et al., 2015).

Personalized medicine in CDI prevention tailor strategies to individual IBD patients by assessing genetic susceptibility, comorbidities, medications and microbiome composition. Predictive models that incorporate clinical data, laboratory markers, and advanced analytics, such as machine learning, help identify high-risk patients. These models, integrated into clinical decision systems, guide providers in selecting targeted preventive measures such as prophylactic antibiotics, adjusting immunomodulators or early use of probiotics or vaccines. This approach enhances the effectiveness of prevention by focusing on patient-specific risks and optimizing therapy decisions. As a result, personalized medicine holds promise for improving CDI outcomes and management in the heterogeneous IBD population (Ashton et al., 2019). Table 3 summarizes future and emerging CDI preventive strategies tailored for IBD patients, emphasizing the promise and challenges of innovative approaches beyond traditional measures.

Given the heterogeneity of both IBD and CDI, personalized medicine, taking into account a patient’s clinical phenotype, genetics, microbiome, and immune status, is critical for optimizing care. Individualized approaches can help stratify risk, guide antibiotic and immunosuppressive stewardship, and support tailored patient monitoring, thus potentially improving outcomes. Advanced predictive models and risk calculators, powered by patient-specific data, can help clinicians pre-emptively identify patients at the highest risk for CDI and recurrence, as well as those who are most likely to benefit from emerging vaccine or microbiota therapies (Mahnic et al., 2022; Alhobayb and Ciorba, 2023; Bai et al., 2023).

Emerging diagnostic technologies, such as NGS, multi-pathogen PCR panels, cytokine profiles, and metabolite-based biomarker assays, are being developed to improve the rapid and accurate discrimination of CDI from IBD flares. Meanwhile, innovative therapies under investigation include defined microbial consortia, targeted live biotherapeutics, phage therapy, monoclonal antibodies, and CDI vaccines. Despite early promise, these tools required rigorous validation specifically in IBD populations to assess their true clinical value, safety, and long-term effects (Bai et al., 2023; Sangurima et al., 2023).

The host-microbiome interaction is fundamental in CDI pathogenesis and recurrence, particularly in the context of IBD, where dysbiosis and immune dysfunction often coincide. Research shows that both IBD and CDI are characterized by reduced microbial diversity, expansion of pathogenic bacteria and impaired colonization resistance, which together exacerbate inflammation and infection risk. Further studies must focus on mechanistic, longitudinal analyses of microbiota composition, host immune responses and the effects of interventions like immunosuppressants, FMT or emerging microbiome-directed therapies in various IBD phenotypes (Mahnic et al., 2022; Alhobayb and Ciorba, 2023).