List of Abbreviations
The American Society for Gastrointestinal Endoscopy
Endoscopic balloon dilation
The European Crohn’s and Colitis Organisation
Inflammatory bowel disease
Ileal pouch-anal anastomosis
Nonsteroidal antiinflammatory drug
Tumor necrosis factor
Video capsule endoscopy
Bezoars are accumulated indigestible foreign materials that can form concretions in the gastrointestinal (GI) tract. They may occur unintentionally or intentionally. Traditionally bezoars are classified into five types based on their composition: (1) phytobezoars (vegetable and fruit fibers); (2) lactobezoars (milk protein); (3) trichobezoars (hair); (4) lithobezoars (stone-like materials), and (5) pharmacobezoars (medications). With the widespread use of wireless video capsule endoscopy (VCE) in patients with inflammatory bowel disease (IBD) since the last decade, capsule retention has also become a well-recognized sequel in the clinical practice.
Bezoars and foreign bodies can be located at any portion of the GI tract, with the stomach being the most commonly reported location in general, particularly for patients with a history of gastrointestinal surgery. The overall incidence of bezoars is low in humans and has been shown to be approximately 0.4%. Although the exact prevalence of GI bezoars in IBD patients is not clear, it is deduced to be higher than that in the general population, due to their tendency to form strictures and frequent requirement for surgical intervention with an altered anatomy. Bezoars and foreign bodies in the GI tract usually need to be removed, as they can cause significant morbidities and even mortality, up to 30% if left untreated. Endoscopic and surgical removals are the two most frequently employed methods in the management of GI bezoars and foreign bodies.
Risk Factors for Bezoars
The pathogenesis of bezoar formation is usually intricate. It is associated with many factors such as improper mastication, dentition problems, high-fiber diet, previous abdominal surgery, nonsteroidal antiinflammatory drug (NSAID) exposure, radiation, bowel obstruction, decreased motility, mental or visual impairment, and hyposecretion of the GI tract. Robles et al. reported on 99 patients with 117 GI bezoars and found that 70% of the patients had previous abdominal surgery, 40% had a history of excessive dietary fiber intake, and 20% had mastication and dentition problems. Most adults with phytobezoars are reported to be males between the ages of 40 and 50 years. On the other hand, trichobezoars usually occur in young women with psychiatric disorders.
In this chapter, we will focus on the IBD-associated factors, including IBD-related surgical issues, risk factors for stricture formation, and the use of VCE in IBD patients.
Restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the surgical treatment of choice for patients with medically refractory ulcerative colitis (UC) or colitis-associated neoplasia. To avoid permanent external appliance in patients who are not qualified for IPAA or who have failed IPAA, the construction of continent ileostomies, such as Kock pouch or Barnett Continent Intestinal Reservoir, is an alternate option. In 2009, we presented a UC patient of pharmacobezoars with 224 dietary supplement tablets retrieved from a Kock pouch. With the accumulation of more cases, we reported 12 patients with ileal pouch bezoars in 2015, of whom 11 had an underlying UC. The frequency of ileal pouch bezoars in patients with UC was found to be 0.4% for J-pouch versus 11.1% for continent ileostomy. Despite GI continuity being completely or partially restored, the altered anatomy in patients with ileal pouches seems to contribute to the development of bezoars.
The underlying disease itself may predispose patients with Crohn’s disease (CD) to the development of GI bezoars. CD patients have been found to have elevated serum levels of peptide YY, a known inhibitor of gastric emptying, which can disrupt the gastrointestinal motility. Moreover, ultrastructural injury and the loss of interstitial cells of Cajal in Auerbach’s myenteric plexus resulting from the intestinal inflammation were observed in CD patients as well. Those conditions may result in abnormal contractions of the intestinal smooth muscle and dysmotility, which is a major risk factor associated with bezoar accumulation.
The tendency to form intestinal strictures in CD patients may further facilitate the development of GI bezoars. CD is characterized by periods of clinical remission alternating with periods of recurrence. Although disease location in CD tends to be stable, disease behavior or phenotype evolves over time. Henriksen et al. showed that among 200 Norwegian patients with CD, 28% had stricturing phenotype at the time of diagnosis. The figure was 33% after 5 years of follow-up. Changes in disease behavior in the subset of patients with CD the Olmsted County, MN cohort diagnosed between 1970 and 2004 were also described. Only 18.6% of the patients had evidence of a stricturing or penetrating intestinal complication at diagnosis or within 90 days of diagnosis. However, the cumulative risk of developing either complication was 50.8% at 20 years after diagnosis.
Since the introduction of antitumor necrosis factor (TNF)-α biologics over 2 decades ago, it has become a part of standard therapy for moderate-to-severe CD or UC, before and after surgery. Anti-TNF along with anti-integrin and anti-interleukin biologics is effective not only for induction therapy in CD patients but also for the maintenance of remission. Despite their therapeutic effects, there is concern that the use of anti-TNF biologics may predispose to strictures or aggravate existing strictures leading to obstructive symptoms. Possible explanation for this phenomenon is that rapid mucosal or tissue healing induced by anti-TNF biologics may cause fibrosis in the submucosa and in the deeper layers of the gut wall. However, the role of anti-TNF biologics use in the development of stricture in CD patients remains controversial, with some studies showing no progression of existing strictures or occurrence of new strictures following the use of anti-TNF biological agents.
CD patients with refractory disease to medical therapy, poor tolerance to medical therapy, or development of complications (fistula, abscesses, or malignancy), are the candidates for surgery. It is estimated that up to 80% of patients with CD will eventually undergo surgical intervention during the life-long course of disease. The surgery leads to an altered anatomy of GI tract, which is predisposed to the development of stricture. The risk of endoscopic recurrence has been shown to be up to 70% within 12–18 months after ileocolonic resection in patients with CD. As disease progresses, anastomotic strictures can be developed with obstructive symptoms in an increasing number of patients.
VCE, first introduced by Iddan in 2000, has become a commonly used modality for the evaluation of the small bowel. In addition to the evaluation for the diagnosis of small bowel CD, VCE also has a role in monitoring disease activity and detecting complications. While stricturing CD is considered as a contraindication to VCE, due to the concern of capsule retention, it is still occasionally used by some clinicians to diagnose and monitor small bowel CD after “assurance” from passage of patency capsule. However, adverse events during VCE procedures such as capsule retention defined as the presence of the device within the GI tract for at least 2 weeks after ingestion requiring further intervention can occur. The retention rate of capsule in CD patients is higher than that in non-CD counterparts, with the reported frequency being 2.2% in patients with occult intestinal bleeding, 5.4% in patients with suspected CD, and 13% in patients with confirmed CD.
Signs and symptoms of GI bezoars are not pathognomonic. Clinical manifestations vary, depending on the location, size and number of bezoars, and the presence or absence of bowel strictures. Patients with GI bezoars may remain asymptomatic or develop life-threatening complications such as impaction, obstruction, perforation, and hemorrhage. Common symptoms usually include abdominal pain or distension, nausea, vomiting, early satiety, anorexia, and weight loss.
A combined assessment of history, clinical presentation, imaging examination, and endoscopy is critical for the diagnosis. A well-taken history and physical examination may elucidate the diagnosis. Imaging examinations such as abdominal radiography with or without contrast, and CT or MRI scan, where bezoars may be seen as a mass or a filling defect are usually helpful. Metal objects or calcified bezoars can easily be detected with radiographic imaging. The most valuable diagnostic and therapeutic procedure for bezoars detection is gastrointestinal endoscopy, which can provide direct visualization and therapeutic intervention. It is important to have abdominal imaging before endoscopy, to provide a roadmap for potential endoscopic therapy.
Due to the rarity of this entity, there has been no consensus on the optimal management of GI bezoars in IBD patients. Medical, endoscopic as well as surgical approaches have been described, with each one having its own pros and cons as the treatment to GI bezoars. The best treatment strategy to each individual patient should be determined on a case-by-case basis. The endoscopist should be familiar with underlying disease, the presence or absence of stricture or surgery-created “gate” (such as stricturotomy or nipple valve of a Kock pouch), and nature of bezoars (for example, breakable noncalcified bezoar; Fig. 27.1 ).
Bezoars may remain in the GI tract without causing symptoms for several years. The “wait and see” strategy might be reasonable in some cases as foreign bodies, such as retained capsule, which may be naturally excreted during the follow-up. The capsules which are retained in strictures with an inflammatory component may improve spontaneously. Apart from the “wait and see” option, medical therapy based on steroids or biologics could be a feasible and effective approach as well.
Chemical dissolution stands for another treatment option, particularly for gastric phytobezoars. A recent systemic review enrolling 24 studies of 46 patients demonstrates that the administration of Coca-Cola alone is effective in gastric phytobezoar dissolution in half of the cases. The mechanisms of bezoar dissolution by Coca-Cola are not understood, but the soft drink has an acidity of pH 2.6, containing carbonic and phosphoric acid resembling gastric acid, which is vital for fiber digestion. Moreover, NaHCO 3 mucolytic effect and CO 2 bubbles may enhance the process of dissolution. Other reported agents used in dissolving gastric bezoars included cellulase, acetylcystine, meat tenderizer, and hydrogen peroxide. However, the majority of available studies are retrospective and noncontrolled trials.
In the past, bezoars or foreign body in GI tract, especially in IBD patients, typically require surgical intervention. The situation may be largely due to the often altered anatomy or the presence of strictures in these patients. However, with the advancement of endoscopic equipment and techniques, a large proportion of patients with GI bezoars can be managed with the endoscopic approach. Endoscopic therapy is useful not only in the diagnosis and retrieval of the bezoars or foreign bodies but also in the treatment of concurrent bowel strictures. The available scopes include esophagogastroduodenoscopy, colonoscopy, balloon-assisted endoscopy, and pouchoscopy. The choice of the scope should be based on the location of the GI bezoars as well as the reachability of each type of scopes. The main advantage of upper endoscopy is the retrieval of bezoars or foreign bodies with possible distal stricture in an antegrade fashion, via pylorus, esophagogastric junction, and upper esophageal sphincter. An overtube may be used to prevent aspiration. In contrast, the retrograde retrieval of bezoars or foreign bodies via colonoscopy or pouchoscopy is more technically challenging and a direct retrieval will involve the passage of the trapped bezoars or foreign bodies through a strictured or anatomically altered bowel segment, such as the nipple valve of a Kock pouch, inlet or outlet of stricturoplasty sites. Furthermore, the removal of bezoars or foreign bodies in the mid-small bowel has been difficult, due to the maneuverability of enteroscope and bowel anatomy. General anesthesia and fluoroscopy guidance are recommended in the latter setting.
Retrograde endoscopic removal of GI bezoars or foreign bodies in IBD patients usually involves fragmenting soft bezoars with a water jet, forceps, or snares. A variety of other methods for harder or calcified bezoars have been described in case reports such as Nd:YAG laser, endoscopic drills, and mechanical, electrohydraulic, extracorporeal lithotripsy. In our experience, the expensive endoscopic mechanical lithotripsy is not effective in the fragmentation of partially or fully calcified bezoars. In contrast, ultrasonic or laser lithotripsy is far more effective. We have performed endoscopic treatment of large calcified bezoars in the Kock pouch in the operating room with the assistance from our urologist team ( Fig. 27.2 ). After fragmentation or if the bezoars are not too large, they can be extracted by large biopsy forceps, basket, Roth Net (US Endoscopy, Mentor, OH) or direct endoscopic suction. The superiority of one endoscopic tool over the others has not been reported in the literature. However, the retrieval of the bezoars or foreign bodies with multi-use basket is the most commonly used approach, possibly due to its safety, easy-use, and cost-effectiveness ( Fig. 27.3 ).