Small bowel obstruction secondary to a plastic bezoar

Abstract

We present a case of a small bowel obstruction secondary to a rare plastic bezoar. A man in their early 20s with autism and an intellectual disability presented with symptoms of small bowel obstruction. CT revealed very subtle signs and, despite passage of gastrografin, ongoing clinical suspicion led to operative management which confirmed the diagnoses of plastic bezoar.

Background

Small bowel obstruction (SBO) is a frequent surgical presentation. SBO is most commonly caused by adhesions, but other aetiologies can include hernia, malignancy, inflammatory bowel disease and foreign bodies (table 1).^{1 2} Further classical signs and symptoms are outlined in table 2 and worrying features that may hasten operative management are seen in table 3.

Table 1.

Common causes of bowel obstruction^{12 17}

Intraluminal	Intrinsic	Extrinsic
Ingested foreign body	Strictures (eg, Crohn’s disease)	Postsurgical adhesions
Gallstone ileus	Intrinsic lesions (lipoma, hamartoma, polyps)	Extrinsic mass (malignant or benign)
		Hernias (eg, internal, inguinal, femoral, ventral)

Table 2.

Classical signs and symptoms of bowel obstruction^{12 18}

Classic symptoms of bowel obstruction	Classic signs of bowel obstruction
Colicky/crampy abdominal pain commonly located in the periumbilical region	Abdominal distention
Vomiting (may occur with or without nausea)	Louder and high-pitched with a tinkling quality bowel sounds on auscultation
Yellow-green or faeculent vomitus	Empty rectum on digital rectal examination
Constipation/Obstipation with dehydration

Table 3.

Symptoms, signs, serum testing and radiographic features that hasten surgical management¹²

Symptoms	Signs	Serum tests	Radiographic
Ongoing obstipation	Tachycardia, febrile, hypotension	Raised inflammatory markers (WCC, CRP)	Small bowel perforation on imaging
	Incarcerated hernia	Electrolyte abnormalities and other metabolic derangement (eg, increased lactate, leucocytosis)	Pneumoperitoneum on imaging
	Erythematous skin changes overlying hernia	Increased urea±creatinine suggestive of worsening renal failure	Closed loop obstruction
	Peritonism		Internal hernia
	Volume depleted state		Distended bowel loops suggestive of high-grade obstruction

CRP, C reactive protein; WCC, white cell count.

A bezoar, a type of foreign body, is a particularly rare cause and accounts for approximately 4% of SBO.^3–6 Phytobezoars (vegetable), trichobezoars (hair), pharmacobezoars (medication) and lactobezoars (milk) are most common.^{4 6 7} However, other compositions have been recorded in the literature. Those at risk of bezoar induced SBO include individuals who have had previous gastric surgery (including vagotomy), increased fibre intake, poor mastication, diabetes, intestinal motility disorders and hypothyroidism.^{4 6–8} Intellectual disability and autism spectrum disorder (ASD) may also predispose an individual to bezoar-induced SBO.^{9 10}

This is an important case study in that it aids clinicians and surgeons in diagnosing and managing plastic bezoar, a rare cause of SBO.

Case presentation

A man in their early 20s presented to hospital with 2 days of nausea, vomiting and central abdominal pain. He had opened his bowels the day prior. He was afebrile, normotensive with a heart rate of 100bpm. His abdomen was soft, non-tender and devoid of any surgical scars or hernia with a normal rectal examination. His medical history included ASD with an intellectual disability that manifested with behavioural issues and being non-verbal.

Investigations

Initial white cell count (WCC) was 15.1 (4–10 × 10⁹ /L) and C reactive protein (CRP) was 9.4 (<5 mg/L). Abdominal X-ray revealed dilated loops of small bowel in the left upper quadrant. Subsequent CT imaging demonstrated a paramidline abrupt transition point with a proximal mottled appearance in the small bowel suggestive of faecalisation (figure 1). In addition, there was a linear hyperdensity that raised the possibility of a foreign body.

Figure 1.

CT scan with views in the transverse, coronal and sagittal planes respectively. The yellow arrow demonstrates the transition point, mottled appearance and linear hyperdensity. The blue line represents the plane for the sagittal section.

At this time, the significance of the linear hyperdensity on CT was unclear. The patient was treated with intravenous fluids, antiemetics and monitored with serial examinations for 24 hours. Over this time, his abdomen remained soft. He remained afebrile and normotensive with a heart rate of 80–100 bpm. He was passing small amounts of flatus, but continued to have intermittent vomits. Repeat WCC remained elevated at 14×10⁹ /L, while the CRP rose to 32.1 mg/L. Oral gastrografin (GG) was given and repeat X-ray demonstrated passage of this contrast into his large bowel with no evidence of any foreign body. GG has therapeutic benefit as it activates movement of water into the small bowel lumen from the oedematous small bowel wall. It also enhances the contractility of the smooth muscle to aid in overcoming the obstruction.¹¹ Despite GG, the patient was unable to open his bowels. Repeat CT demonstrated persistent findings of SBO along with the linear hyperdensity in question (figure 2).

Figure 2.

CT scan with views in the transverse, coronal and sagittal planes respectively demonstrating persistent SBO, the linear hyperdensity along with reactive free fluid and evidence of GG in the large bowel. The blue line represents the plane for the axial section. GG, gastrografin; SBO, small bowel obstruction.

Differential diagnosis

Differentials for the aetiology of an SBO, in a young patient, include adhesions, strictures, internal hernias, intussusception or foreign body. Adhesions can either be congenital, or secondary, or due to previous open surgery or a significant inflammatory process. After multiple CT scans of the abdomen, there was no evidence of internal herniation, intussusception or an inflammatory process or other common causes such as those in table 1, however, there was suspicion of foreign body obstruction.

It can be difficult for clinicians to assess if it is a complete or incomplete bowel obstruction through radiographical changes alone. A complete obstruction inhibits passage of all bowel contents whereas a partial obstruction allows some liquid or gas to pass through the point. Low-grade partial obstructions are prone to spontaneous resolution with conservative management however, less than 20% of patients with a high-grade partial or complete obstruction resolve with non-operative management.¹² Other clinical indicators for concern seen in table 3 guide emergent surgical intervention.¹³

Treatment

Initially, non-operative management was performed, and the patient was treated with intravenous fluids, antiemetics and monitored with serial examinations for 24 hours. However, the obstruction did not resolve and as such operative management was indicated.

A small midline laparotomy was carried out. Distal small bowel inspection demonstrated an obvious obstruction that was quite hard on palpation. As it was a large mass of uncertain aetiology that could not be easily separated from bowel, a resection was performed that revealed a 6 cm compact structure that, on further inspection, was a plastic glove bezoar (figure 3). The remaining bowel was inspected to ensure no further bezoars were present and a side to side two layered hand-sewn anastomoses was performed.

Figure 3.

Resected specimen of small bowel with plastic bezoar.

Outcome and follow-up

The patient went on to make a full recovery following his laparotomy. He was able to tolerate a normal diet and open his bowels without issue prior to discharge from hospital. He was followed up in the surgical outpatient clinic after discharge and remained well.

Discussion

Diagnosis of an SBO secondary to plastic bezoar can be difficult due to its radiological appearance, and as it is less common than other forms of bezoars like phytobezoars and trichobezoars.^{4 8} It is especially challenging to diagnose in persons with intellectual disability and ASD due to communication limitations. Careful attention to the patient’s history is key, as this may allude to a multifactorial, synergistic predisposition to bezoar SBO, which may aid diagnosis.

As seen in this case, plain film does not always confirm the diagnosis of a bezoar. Therefore, CT is useful in confirming the diagnosis of SBO, the site of obstruction, and any other potential bezoars.^{1 2 5} Occasionally, a bezoar demonstrates a mottled gas appearance surrounding a foreign body with a transition point suggestive of SBO.^{4 5} However, this can be misinterpreted as a small bowel faeces sign.⁶ Barium studies and ultrasound can also be considered.⁶ Flagging the concern of a bezoar with the radiologist may help in choosing the best imaging modality, dependent on patient characteristics, and may aid in a more accurate diagnosis.

In the first instance, barium swallow or ultrasound are preferred imaging modalities in a paediatric patient. However, CT in our case was chosen as it was a less invasive and less time consuming imaging modality. Barium swallow requires more time due to multiple X-rays, body positioning and breath holding at times. As such the complexity of obtaining a barium swallow would be technically difficult to achieve in this particular patient. In addition to this, the patient expressed discomfort with any pressure on his abdomen and so to prevent further patient distress an ultrasound was not carried out. Thus, CT was the best suited imaging modality based on this individual patient’s circumstances and background. However, CT is limited in the setting of foreign bodies with a low radiopacity with a reported sensitivity of approximately 68% and specificity of 98% for the detection of all types of foreign bodies.^{14 15} This is in comparison to ultrasound which has a reported sensitivity of approximately 94% and specificity of 99% for detection of foreign bodies.¹⁶

Depending on the clinical status of the patient, along with the radiological findings, different management modalities of bezoar SBO can be implemented.^{4 5} Conservative observation, especially if the bezoar is small and mobile, can be undertaken.¹ Endoscopic removal is optional if the obstruction is proximal.^{3 8 9} Operative intervention, including fragmentation and milking of the bezoar into the large bowel⁷ or bowel resection, can be considered. Whichever management option is chosen, the surgical team must always monitor for complications of SBO such as bowel ischaemia, perforation and bacterial translocation. In patients with ASD and intellectual disability, referral to psychiatry warrants consideration to minimise the risk of future self-harm.

Learning points

• Small bowel obstruction is a frequent surgical presentation of many patients to the hospital. Clinicians and surgeons must have a knowledge of both the common and rare causes.

• Bezoar, especially a plastic bezoar, is a rare cause of small bowel obstruction. This can be especially difficult to diagnose and a high index of suspicion should be maintained.

• Small bowel obstruction from a bezoar should be suspected in patients with an intellectual disorder or psychiatric disorder, such as Autism, when the common aetiologies have been excluded.

Ethics statements

Patient consent for publication

Consent obtained from parent(s)/guardian(s).