Abstract The NICE (Natural orifice IntraCorporeal anastomosis with transrectal Extraction) procedure represents an evolution in minimally invasive colorectal surgery, combining robotic precision with natural orifice specimen extraction to minimize abdominal wall trauma. The technique involves mesenteric-sparing resection of the diseased segment, transrectal natural orifice specimen extraction, and creation of an end-to-end intracorporeal anastomosis, thereby eliminating the need for an abdominal extraction-site incision and avoiding the intersecting staple lines inherent to a conventional double-stapling technique. Multiple publications have demonstrated the feasibility, reproducibility, and favorable outcomes of this approach, with 100% success rates for intracorporeal anastomosis and 95 to 100% success rates for transrectal extraction in large consecutive series. The NICE procedure has become the standard of care at our institution and has been increasingly adopted by other centers. This article outlines the history, indications, and key technical steps necessary for safe and successful performance of the NICE procedure, presented in a standardized, stepwise manner to provide surgeons with a reproducible and practical framework for adopting the technique in the management of diverticular disease. Foundational principles include mesenteric-sparing resection with division above the superior rectal artery, systematic mobilization of the pararectal and anterior rectal reflections to straighten and elongate the rectum, and protection of the rectal cuff during extraction using an Alexis wound retractor (Applied Medical, Rancho Santa Margarita, CA). An end-to-end anastomosis is preferred to avoid intersecting staple lines and is achieved through purse-string suture placement on the proximal colon and secure closure of the rectal cuff. In select cases involving thickened mesentery from chronic diverticular disease, a mesenteric-shaving technique may be used to permit safe extraction of a bulky specimen. Compared with conventional minimally invasive approaches that require a mini-laparotomy extraction site, the NICE procedure is associated with an earlier return of bowel function, a shorter length of stay, reduced postoperative pain and opioid consumption, and fewer wound-related complications, without an increase in operative time or overall complication rates.
Abstract Cryptoglandular anorectal abscess and fistula-in-ano represent a disease continuum and one of the most common benign anorectal disorders. Accurate estimation of incidence and prevalence remains difficult due to variable presentation and reporting. Prompt incision and drainage remain the cornerstone of abscess treatment. Aspiration alone is not recommended. External drainage is preferred for perianal and ischiorectal abscesses, while transrectal drainage is used for supralevator and submucosal collections to minimize iatrogenic fistula formation. Intersphincteric abscesses should be drained either transrectally or via an incision over the intersphincteric groove. Routine wound packing is not supported by randomized evidence, as it increases pain without reducing recurrence. Selective use of mushroom catheters or Penrose drains improves patient comfort and facilitates drainage of large cavities. Routine postoperative antibiotics do not prevent recurrent abscesses, but they may reduce subsequent fistula formation. Primary fistulotomy during abscess drainage is safe for low fistulas in selected patients with accurate anatomic assessment and good baseline continence, significantly lowering recurrence rates compared with drainage alone. High fistulas should not undergo fistulotomy. Draining setons are valuable for high or complex fistulas to control sepsis, prevent recurrent abscesses, and allow inflammation to subside before definitive repair. Cutting setons have largely fallen out of favor due to elevated incontinence risk. Definitive sphincter-preserving fistula repair should be delayed until acute inflammation resolves.
Abstract Anal fistula is a common condition encountered in colorectal practice, most often arising from cryptoglandular infection in the anal canal. It usually starts in the intersphincteric space, mostly as an anorectal abscess and spreads in different directions, which results in various configuration of tracts that are classified based on their position with respect to the anal sphincters. The primary goals of management are to eliminate sepsis, achieve durable healing, and preserve anal sphincter function. While standard treatment algorithms are effective for most primary, uncomplicated fistulae of cryptoglandular origin, a subset of patients presents with clinical scenarios that demand a more nuanced and individualized approach. These special situations include recurrent fistula, fistula in pediatric patients, anterior fistula in women, and fistula occurring in immunocompromised individuals. In such settings, the risk of treatment failure, recurrence, or impairment of continence is higher, and management must be individualized. Recurrent fistulae often indicate unrecognized complexity or inadequate prior treatment. Pediatric fistulae typically follow a different natural history and are often amenable to more conservative management. Anterior fistulae in women pose a unique challenge due to the inherent vulnerability of the anterior sphincter complex and the heightened risk of postoperative incontinence. Immunocompromised patients, including those with conditions such as Crohn's disease or human immunodeficiency virus, often present with additional challenges related to impaired healing and increased susceptibility to infection. This chapter outlines the key considerations in these scenarios, with emphasis on risk stratification, appropriate evaluation, and selection of sphincter-preserving treatment strategies to optimize both healing and functional outcomes.
Abstract Diverticular disease is a common disease of the Western world; however, its epidemiology, presentation, and management have changed dramatically over the past century. Initially described in the 1700s, diverticular disease became an increasingly frequent finding, especially as imaging techniques were developed. The “fiber hypothesis” was proposed in the 1960's to explain the rising incidence of diverticular disease in westernized countries, suggesting it was secondary to reduced fiber in the diet. However, more recent studies suggest it is multifactorial, including genetics, lifestyle, and medications. Overall, the incidence of diverticular disease is increasing, and there is a rising trend of male patients below the age of 50 who are presenting with acute diverticulitis. Traditionally, diverticular disease has been right-sided in Eastern populations compared to the West, where it is commonly found in the sigmoid colon. More recently, though, there is a rising incidence of bilateral and left-sided disease in Eastern countries. Global disparities in the care and outcomes of diverticular disease are becoming more evident. More socio-economically deprived populations have higher rates of emergency admissions, complications, and reduced access to elective care. There are global differences in the rates of elective resections, the use of antibiotics, and the outpatient treatment of uncomplicated diverticulitis. This article will explore the implications of the topics outlined above. A better understanding of the changing epidemiology of diverticular disease and associated disparities in care is essential to developing more equitable, evidence-based management in diverse populations.
Abstract Proctocolectomy with ileal pouch-anal anastomosis is the preferred surgical treatment for refractory ulcerative colitis. Pouchitis, defined as inflammation of the ileal pouch, develops in approximately 80% of cases following colectomy. Although most patients will initially respond to antibiotic therapy, recurrence is common, suggesting a more complex pathophysiology beyond the microbiome, similar to what is seen in inflammatory bowel disease. In this review, we provide an overview of inflammatory pouch disorders, including acute pouchitis, chronic antibiotic-dependent pouchitis, chronic antibiotic-refractory pouchitis, Crohn's-like disease of the pouch, and cuffitis, as well as outline a stepwise approach to diagnosis of management. We also highlight future directions and emerging therapies in the field.
Abstract The link between diverticular disease and colon cancer has long been questioned given the often-overlapping risk factors for development. With the high burden of diverticular disease in the United States, a link, if present, could translate into a large volume of affected individuals and could inform further decisions about how patients are counseled regarding surgery and additional treatments. We will discuss the literature that reviews these associations as they pertain to diagnosis and management, which suggests that there is no direct evidence which supports diverticulitis as an independent risk factor for developing colorectal cancer and that high-quality colonoscopic evaluation should be performed after diverticulitis as the attack may be cancer in disguise.
Abstract The ileal pouch–anal anastomosis (IPAA) remains the standard of care for restoration of anal continuity in patients undergoing total proctocolectomy across disease etiology, including ulcerative colitis, indeterminate colitis, or familial adenomatous polyposis. Pouch function is a direct result of the complex concept of this pouch physiology. Numerous studies have reported high satisfaction results in patients undergoing pouch reconstruction. However, there is still a subset of patients who report poor pouch function. As IPAA construction's sole purpose is lifestyle improvement and modification in patients whose only other option is a permanent ostomy, patient satisfaction and quality of life (QOL) are arguably the most important metrics in the evaluation of pouch success. Historically, pouch function and QOL metrics were based on physician-derived criteria, namely fecal incontinence and urgency. Newer research has shed light on the importance of patient input regarding pouch symptoms and consequences and the subsequent perception of QOL. Surprisingly or not, these differ from the symptoms physicians had previously valued. Significant work has been completed in developing standardized tools and metrics to continue to evaluate the QOL for these patients. Foundationally understanding and valuing the patient experience, expectations, and subsequent effect on QOL is critical in counseling pre- and postoperatively IPAA patients. Additionally, understanding the effect of their experiences on QOL is a cornerstone in supporting patients in any intervention concerning their continued disease process and should be tailored and done so in a team-based approach, inclusive of the patient themselves.
Abstract Diverticular disease is common, but its clinical presentation and course from silent diverticulosis to diverticulitis or symptomatic diverticular disease remains unpredictable. Genetic studies have revealed a substantial heritable component, implicating extracellular matrix integrity, and neuromuscular function as key pathways. Large-scale genome-wide association studies have enabled the development of polygenic risk scores, which show promise for identifying individuals at increased risk, although their predictive advantage over demographic factors such as age and sex is modest. Increasing data provided by transcriptomic, epigenomic, and proteomic analyses will complement recent genetic discoveries, thereby providing an understanding of how gene regulation is affected by the environment. Integrating this emerging knowledge with microbiome studies and metabolomics could enable powerful, tailored “multiomic” prediction tools capable of delivering more accurate and clinically meaningful risk stratification.
Abstract Diverticulitis remains a significant and increasingly common health burden in North America. Historically, elective colectomy was recommended based on rigid criteria, typically after more than two episodes of uncomplicated diverticulitis or a single episode of complicated disease. However, emerging guidelines now support a more individualized, symptom-based approach that incorporates disease severity, comorbidities, and quality-of-life considerations. Evidence indicates that recurrent uncomplicated diverticulitis often follows a benign course, with most patients avoiding surgery even after multiple episodes. In contrast, chronic conditions such as smoldering diverticulitis or symptomatic uncomplicated diverticular disease may mimic acute recurrence but require careful diagnostic evaluation. Although randomized controlled trials have demonstrated that elective resection can improve gastrointestinal quality of life in select patients, these benefits must be weighed against the risks of perioperative complications and potential long-term bowel dysfunction. For complicated diverticulitis, surgery remains clearly indicated in the presence of fistulas or strictures, whereas the role of elective colectomy following successful treatment of diverticular abscess remains controversial. Ultimately, surgical decision-making should be anchored to shared discussions that consider patient preferences, symptom burden, and individualized risk profiles.
Abstract The management of diverticulitis has evolved substantially over the past two decades, paralleling major advances in minimally invasive surgery. While laparoscopic colectomy was shown to be safe and effective compared with open surgery for uncomplicated disease with lower complication rates, faster return of bowel function, and shorter hospital stays, its application to complicated or recurrent diverticulitis was limited by difficult anatomy, technical constraints, and surgeon comfort. The advent of robotic surgery and robotic technology has transformed the clinical landscape and promoted the adoption of minimally invasive techniques in colorectal surgery by offering superior visualization, enhanced dexterity with wristed instrumentation, and improved ergonomics. These capabilities are advantageous in deep pelvic dissections and other scenarios where conventional laparoscopy is more challenging. The robotic approach is associated with reduced intraoperative blood loss, fewer conversions to open surgery, and faster functional recovery. Technological innovation continues to accelerate with the expansion of robotic platforms beyond the da Vinci model, including the single-port robot, the miniaturized MIRA system, and the new multi-arm modular Hugo and Versius systems. These emerging technologies incorporate features, such as flexible architectures, augmented visualization, haptic feedback, and integrated artificial intelligence to improve operative precision, communication, and workflow. Market expansion and diversification—driven by new manufacturers and expiring patents—has spurred competition that will hopefully reduce costs and broaden access. Early clinical experiences suggest that these platforms are safe and feasible in the management of diverticulitis. Despite rapid progress, controversy remains regarding the definitive superiority of robotics over laparoscopy. Current evidence supports a tailored and patient-centered approach that considers disease complexity, medical comorbidities, surgeon experience, and institutional resources. As the field advances and more randomized trials are performed, robotic technology is poised to further refine the surgical management of diverticulitis and contribute to improved patient safety, functional recovery, clinical outcomes, and long-term quality of life.
Abstract Diverticular disease, particularly perforated diverticulitis (PD), is a growing global health concern, with its management traditionally involving non-restorative resections, which significantly impact patients' quality of life. More recently, there has been a paradigm shift toward performing primary anastomosis without diversion (PAWOD) for these patients. This review aims to evaluate and discuss the safety and practicality of PAWOD in acute PD, a topic that remains controversial. Various surgical options based on the location of the disease and patient stability have been explored, including considerations for pan-diverticular disease. We highlight the factors favoring PAWOD while also acknowledging the continued relevance of protective stomas and non-restorative surgery. The review delves into technical considerations, including the role of minimally invasive surgery, innovative surgical techniques, and adjuncts to reduce anastomotic leaks. While PAWOD is a safe and increasingly feasible option for appropriately selected patients, its widespread adoption still faces practical challenges, including surgeon expertise and institutional resources. With ongoing advancements and dedicated training, the criteria for PAWOD are likely to broaden, ultimately enhancing patient outcomes in emergency surgery for PD.
Abstract The optimal management of diverticulitis in young and immunocompromised patients remains controversial, particularly regarding whether these groups warrant a lower threshold for surgery. Historically, young patients were often offered elective colectomy after the first episode of diverticulitis because of concerns regarding recurrence and more aggressive disease. However, contemporary evidence shows that although younger patients may experience higher recurrence rates, they are not at increased risk for complicated recurrence, emergency surgery, or mortality compared with older adults. Nonoperative management is successful in most cases, supporting an individualized rather than age-based surgical approach. Immunocompromised patients, including those with solid organ transplantation, malignancy, chemotherapy exposure, chronic steroid use, or autoimmune disease requiring immunosuppression, represent a higher-risk population. These patients more commonly present with complicated diverticulitis, perforation, sepsis, and atypical symptoms that may delay diagnosis. Although uncomplicated disease can often be managed nonoperatively, immunocompromised patients experience higher rates of emergent surgery, stoma creation, postoperative complications, and mortality, particularly when surgery is performed in a non-elective setting. Current evidence does not support lowering the surgical threshold solely on the basis of young age or immunosuppression status. Instead, management should remain individualized, incorporating disease severity, recurrence pattern, comorbidities, operative risk, and patient preferences. Further research is needed to better define optimal surgical timing and patient selection in these two populations.
Abstract The procedure to redo a pelvic pouch is much more complicated than constructing the primary pouch. It is important to have a team-based approach to determine the etiology of the pouch problem. While not all pouches should be redone, some indications for the redo pouch procedure include chronic fistula or sepsis, stricture of anastomosis or afferent limb, torsion, neoplasia or dysplasia, and efferent outlet obstruction. Redo pouches have higher complication rates and should not be undertaken by casual pouch surgeons. In the preoperative setting, nutritional optimization and current imaging are required. All sepsis must be drained, and fecal diversion with a “thoughtful stoma” may be constructed to aid in sepsis control. Surgery is typically performed via an open approach and ureteric stents are utilized. Meticulous dissection is required, and intraoperatively, the decision must be made whether to repair the existing pouch or construct a new pouch. Rarely, with redo surgery can the ileal pouch anal anastomosis be stapled. Therefore, a mucosectomy and handsewn pouch anal anastomosis is needed. Long-term function and pouch retention depend on the initial diagnosis and etiology of the pouch problem. That said, improved quality of life and acceptable long-term function can be achieved for patients who undergo a redo pouch procedure.
Abstract Diverticulosis and its progression to diverticulitis remain a highly studied topic in gastrointestinal disease. Although up to 60% of the population in Western countries may have diverticulosis, risk factors for progression to diverticulitis, particularly complicated disease that requires surgical management, remain poorly characterized and lack validated, universally accepted risk stratification tools. The classically recognized risk factors of diverticulitis, like diet, activity level, and other modifiable behaviors, are now more clearly linked to chronic inflammation and its effects on the gut microbiome and multiple areas of gene expression, including connective tissue function and colon motility. More work remains to study the exact extent to which risk for severe diverticulitis is modifiable or whether this process is influenced more by nonmodifiable genetic factors. This information can help inform screenings of patients diagnosed with diverticulitis or those with family histories of the disease. Overall, better prediction of diverticulitis occurrence and progression to complications will help surgeons promote an individualized, patient-centered approach to disease education and operative management of patients.
Abstract Diverticulitis, an inflammatory complication of colonic diverticulosis, represents a major public health burden, accounting for substantial morbidity and healthcare expenditures. Although traditionally viewed as a purely mechanical process driven by obstruction of diverticular lumens, recent advances suggest dysregulated host immune responses and gut microbial imbalance in its pathogenesis. This evolving understanding has stimulated interest in immunomodulatory and non-surgical therapeutic strategies to prevent and treat diverticulitis. Inflammatory mediators including C-reactive protein (CRP), interleukin-6, interleukin-10, and tumor necrosis factor-α correlate with disease severity and may persist chronically, suggesting a sustained mucosal immune activation. Pharmacologic approaches targeting this axis have yielded mixed results. Systemic corticosteroids and biologic immunomodulators increase the risk of diverticular complications, whereas mesalamine shows inconsistent benefit limited to symptom relief in chronic disease. Rifaximin, a minimally absorbed antibiotic with local anti-inflammatory and microbiota-modulating properties, may modestly reduce recurrence when combined with a high-fiber diet but remains unsupported by major guidelines. Non-pharmacologic strategies, including fiber-rich and anti-inflammatory diets, appear to mitigate disease risk, possibly through favorable modulation of microbial metabolism and short-chain fatty acid production. Emerging microbiome-directed therapies such as probiotics and fecal microbiota transplantation (FMT) show promise in preliminary trials for reducing inflammation and recurrence, though data remain heterogeneous and underpowered. Future research should clarify mechanistic links between immune regulation, microbial ecology, and mucosal integrity, and define standardized protocols for probiotic and FMT interventions. Ultimately, understanding and manipulating the immune-microbiome axis may transform diverticulitis management, offering non-surgical alternatives to colectomy for recurrent disease.
Abstract This comprehensive review explores the current landscape and future perspectives of emerging technologies in colorectal surgery, emphasizing their application to diverticulitis—a condition that continues to challenge surgeons with complex inflammatory pathology, variable tissue quality, and high anastomotic risk. The discussion focuses on fluorescence dyes, artificial intelligence (AI) systems, magnetic compression anastomosis (MCA), and next-generation stapling platforms. Each of these innovations offers new opportunities to improve surgical precision, reduce postoperative complications, and personalize anastomotic management in patients with diverticulitis. Fluorescence imaging with indocyanine green (ICG) has become an essential intraoperative tool for assessing bowel perfusion and anastomotic viability in left-sided colonic resections performed for diverticulitis. Adequate perfusion is a major determinant of anastomotic healing, particularly in inflamed or thickened segments where vascular compromise is common. Quantitative fluorescence angiography provides real-time data on tissue oxygenation, allowing surgeons to identify well-perfused margins and optimize anastomotic placement. By visually confirming blood flow, ICG technology assists in determining whether primary anastomosis is safe or whether diversion is advisable, contributing to more informed intraoperative decision-making. AI represents a transformative advance in the surgical management of diverticulitis. AI-driven diagnostic algorithms can distinguish between diverticulitis and other colonic pathologies, improving the accuracy of preoperative planning. During surgery, AI systems that integrate imaging and perfusion data can help predict anastomotic leak risk, guide the use of protective stomas, and enhance postoperative surveillance. Machine learning models analyzing electronic health data can also stratify patients based on disease severity, supporting individualized approaches to resection and reconstruction. These applications pave the way for a data-informed, precision-guided strategy that complements surgical expertise in complex inflammatory disease. Magnetic compression anastomosis, or magnamosis, introduces a minimally invasive alternative to traditional sutured or stapled connections. In the context of diverticulitis, where postoperative fibrosis and strictures can compromise bowel continuity, MCA offers a novel means of restoring luminal patency without reoperation. By using controlled magnetic force to re-establish a channel through scarred or stenotic tissue, this approach minimizes trauma and promotes natural healing. Its potential use for managing anastomotic narrowing following resection for diverticulitis represents a promising step toward less invasive, function-preserving interventions. Advances in stapling technology further enhance anastomotic safety in diverticulitis surgery. New circular staplers with triple-row configurations, powered firing mechanisms, and automated compression control improve tissue apposition and perfusion in areas affected by chronic inflammation. These innovations reduce the variability of manual stapling, standardize compression across the staple line, and help protect against ischemia in compromised tissue. Such precision-engineered systems are especially valuable in diverticulitis, where tissue thickness, edema, and fragility increase the technical demands of colorectal anastomosis. Together, these emerging technologies signify a shift toward precision colorectal surgery tailored to the biological and anatomical challenges of diverticulitis. By integrating fluorescence-guided perfusion assessment, AI-based risk prediction, magnetic compression systems, and advanced stapling devices, modern surgery is moving beyond the traditional dichotomy of primary anastomosis versus diversion. The goal is not only to reduce anastomotic leak rates but to create a new paradigm of safe, individualized, and minimally invasive treatment for diverticulitis.
