Obstructive rectal cancer incidentally diagnosed after a barium meal study: a case report of sequential endoscopic stenting and elective laparoscopic resection

Abstract

Introduction:

Barium meal study (BMS) has been widely used in Japan for gastric-cancer screening. Although complications are rare, intestinal obstruction due to retained barium can occur, especially in patients with preexisting gastrointestinal pathology. However, incidental diagnosis of obstructive rectal cancer after a BMS is extremely rare.

Presentation of case:

A 72-year-old asymptomatic man underwent a BMS following a positive fecal occult blood (FOB) test. Four weeks later, he developed constipation and abdominal distension. Imaging revealed retained barium and rectal wall thickening. Emergency colonoscopy identified an obstructive rectal tumor, and a self-expandable metallic stent was placed. After successful clearance of retained barium, elective laparoscopic anterior resection with primary anastomosis was performed. Postoperative recovery was uneventful. Pathological diagnosis was pT4aN1aM0 rectal cancer. The patient completed adjuvant chemotherapy and remains disease-free 12 months postoperatively.

Discussion:

This case illustrates a rare diagnostic pathway in which obstructive rectal cancer was incidentally diagnosed after BMS. It is important to consider underlying malignancy when prolonged constipation develops following BMS. Limitations of this report include the inability to perform magnetic resonance imaging owing to stent placement, which compromised local staging and may have influenced the decision to omit neoadjuvant therapy. Furthermore, the delay in acting upon the positive FOB test may have contributed to disease progression, underscoring the need for improved coordination between screening and diagnostic services.

Conclusion:

To our knowledge, this is the first reported case of obstructive rectal cancer incidentally diagnosed after a BMS and successfully managed with sequential endoscopic stenting and single-stage laparoscopic resection.

Introduction

In Japan, barium meal studies (BMS) have traditionally been used as a radiographic method for gastric cancer screening. The reported detection rate of gastric cancer through radiographic examinations is 0.05–0.32%^[1^]. Historical cohort and case–control studies suggest that radiographic screening may have reduced gastric cancer mortality by 40%^[2^].

However, complications associated with BMS have been reported, including barium aspiration, intestinal perforation, and intestinal obstruction with or without barolith (inspissated barium) impaction^[3–5^], although the overall incidence is rare (42.8 per 100 000 examinations)^[2^]. Careful selection for BMS is essential, as a systematic review found that more than 10% of patients presenting with barolith-related intestinal obstruction also had underlying gastrointestinal malignancy^[5^].

HIGHLIGHTS

• A 72-year-old patient retained barium after a barium meal study (BMS).

• A rare diagnostic path of incidental obstructive rectal cancer diagnosis was followed.

• Successful management included endoscopic stenting and laparoscopic resection.

• Underlying malignancy is probable when prolonged constipation develops after a BMS.

This report describes a rare case of intestinal obstruction secondary to advanced rectal cancer, incidentally identified following a BMS performed for gastric-cancer screening. Although BMS was not intended for colorectal evaluation, the retained barium prompted further investigation, and the patient subsequently underwent elective laparoscopic resection following successful endoscopic stenting. This case is reported in line with the Surgical CAse REport (SCARE) guidelines^[6^].

Case presentation

A 72-year-old man had a positive fecal occult blood (FOB) test during a health checkup. His medical history included appendectomy and reflux esophagitis. He reported occasional alcohol consumption and a 20-year history of smoking. Although the FOB-test result was positive, the patient declined the recommended follow-up examination at that time. He remained asymptomatic and underwent a BMS for gastric cancer screening. Following the examination, the patient experienced persistent constipation and progressive abdominal distension, with no bowel movements for 4 weeks. Abdominal radiography performed by his local physician revealed retained barium, with inspissated contents suggestive of intestinal obstruction (Fig. 1A). Computed tomography (CT) demonstrated rectal wall thickening with luminal narrowing containing barium, suggestive of rectal cancer (Fig. 1B). He was referred to our hospital the same day.

Figure 1.

Images before treatment.

(A) Abdominal radiography showing retained, inspissated barium consistent with intestinal obstruction. (B) Contrast-enhanced computed tomography (CT) demonstrating circumferential rectal wall thickening with luminal narrowing containing retained barium (yellow arrowheads), suggestive of rectal cancer. (C) Colonoscopy revealing an impassable, circumferential, ulcerative tumor located 13 cm from the anal verge. (D) Fluoroscopic image during colonoscopy showing irregular deformation of the rectosigmoid wall (yellow arrowheads).

Emergency colonoscopy, performed without bowel preparation, identified an impassable circumferential ulcerative tumor located 13 cm from the anal verge (Fig. 1C, 1D). A self-expandable metallic stent (SEMS: Niti-S, 22 mm × 10 cm, Century Medical, Japan) was placed immediately (Fig. 2A). Biopsy confirmed adenocarcinoma. The following day, abdominal radiography showed stent patency, and 4 days later, clearance of retained barium was evident (Fig. 2B). With full-bowel preparation using 2 L of polyethylene glycol solution, total colonoscopy confirmed proper stent position (Fig. 2C) and excluded additional proximal lesions. His symptoms improved, allowing resumption of a low-fiber diet and daily magnesium oxide.

Figure 2.

Images after stent placement.

(A) Endoscopic placement of a self-expandable metallic stent. (B) Abdominal radiography showing stent patency (yellow arrowheads) and clearance of retained barium. (C) Fluoroscopic image during colonoscopy confirming correct stent position (yellow arrowheads). (D) Abdominal CT showing circumferential rectosigmoid wall thickening (yellow arrowheads) and enlarged lymph nodes within the mesorectum (green arrowhead).

The patient’s height was 161.7 cm, weight 53.3 kg, and body mass index 20.4 kg/m². Blood tests, including tumor markers were normal (CEA 3.7 ng/mL and CA19-9 < 2.0 U/mL). Contrast-enhanced abdominal CT showed circumferential wall thickening in the rectosigmoid region and enlarged lymph nodes within the mesorectum (Fig. 2D). Magnetic resonance imaging (MRI) was not performed because of the SEMS, which can cause significant susceptibility artifacts and comprise image quality.

Based on these findings, he was diagnosed with cT4aN1bM0 (cStage IIIB) rectal cancer. The multidisciplinary team discussed treatment options. Given the tumor location at the rectosigmoid junction, potential risks associated with prolonged obstruction, and the SEMS, which may limit the feasibility of radiotherapy and use molecular-targeted agents, upfront surgery was prioritized over neoadjuvant therapy. On hospital day 21, laparoscopic anterior resection with D3 lymph node dissection was performed following 2 days of bowel preparation with magnesium citrate solution. Operative time was 187 min with blood loss of 10 mL. Macroscopic examination of the resected specimen revealed circumferential tumor without residual barium (Fig. 3). Postoperative recovery was uneventful, and the patient was discharged on postoperative day 9. Pathology confirmed pT4aN1aM0 (pStage IIIB).

Figure 3.

Resected specimen.

Macroscopic examination of the resected specimen demonstrating and ulcerated circumferential rectal tumor without residual barium.

He subsequently received adjuvant chemotherapy: six cycles of CAPOX (oxaliplatin 180 mg/body and capecitabine 3000 mg/day) followed by two cycles of capecitabine monotherapy (3000 mg/day). At 12 months postoperatively, he remained in good health with no evidence of recurrence.

Discussion

Intestinal obstruction is a rare complication of BMS. Following oral administration, barium is typically cleared from the colon within 1 week in 57% of patients and within 4 weeks in most of the remainder^[7,8^]. Retention beyond this period significantly increases the risk of obstruction. Constipation is the most common symptom, and the left colon is the most frequently affected site^[5,8–10^]. A systematic review reported that half of the patients with barium-induced obstruction developed symptoms more than 5 weeks after a BMS, with onset ranging from 2 days to 2 years^[5^]. Several factors contribute to obstruction, including advanced age, dehydration, electrolyte imbalance, luminal narrowing, and conditions or medications that impair colonic motility such as Parkinson’s disease, diabetes, and pseudo-obstruction^[5,8,11^].

Barolith formation can also occur in patients without predisposing pathology. Risk factors include inadequate dilution of contrast medium, ingestion of solid food before the examination, and failure to administer laxatives afterward^[8^]. For prevention, the use of well-suspended isotonic barium preparations, hydration before the examination, maintenance of normal activity, adherence to a high-fiber diet for 2–3 days, post-examination laxatives or lactulose, and close monitoring of bowel movements are generally recommended^[10,12^]. Pathan et al additionally suggested follow-up imaging 2–3 days after BMS, with immediate laxative administration if barium residue is detected^[7^].

In this case, advanced rectal cancer caused luminal narrowing and led to obstruction 4 weeks after a BMS. As more than 10% of patients with barolith-related obstruction harbor gastrointestinal malignancies^[5^], occult disease should be considered, particularly when constipation is observed before or after BMS. Early recognition is essential and can be supported by careful preexamination history taking, follow-up interviews or visits, and imaging when symptoms arise^[8,12^].

Management strategies for intestinal obstruction after BMS range from conservative to surgical, depending on symptoms, severity, and location^[5,12^]. Conservative approaches are preferred in the absence of perforation or ischemia and include hydration, manual disimpaction, enemas, gastrografin, laxatives, lactulose, and endoscopic dissolution^[5,12^]. Surgical intervention is indicated when these measures fail or when perforation is present. A systematic review found that resection and anastomosis was the most common surgical method for barolith removal, followed by colotomy and colostomy, all performed via laparotomy^[5^]. Another case series reported that approximately 78% of patients underwent Hartmann’s procedure or colostomy, while a minority had simple suture closure in cases of perforation^[13^].

The delay in acting upon the positive FOB test highlights a gap in the screening workflow. Conventionally, a positive FOB result should prompt colorectal evaluation. Here, however, the patient did not undergo the recommended follow-up, and rectal cancer was eventually diagnosed through an unusual modality (BMS). This delay may have contributed to disease progression and underscores the importance of timely response to screening results and improved coordination between screening programs and diagnostic services.

In our patient, endoscopic stent placement was chosen as the initial treatment for obstruction. After barium clearance with laxatives and bowel preparation, elective resection with primary anastomosis was performed. To our knowledge, this is the first report of sequential treatment consisting of endoscopic stenting followed by single-stage laparoscopic resection for obstructive rectal cancer diagnosed after BMS. SEMS use as a “bridge-to-surgery” in obstructive colorectal cancer is well-established and widely accepted. However, unique in this case was its unusual diagnostic sequence; the patient underwent a BMS for gastric-cancer screening, inadvertently revealing retained barium and leading to the rectal-cancer diagnosis. In the clinic, cross-sectional imaging and endoscopy are primarily used for colorectal evaluation and upper gastrointestinal contrast studies are uncommon. Therefore, the incidental detection of obstructive rectal cancer following BMS represents a rare diagnostic pathway, potentially warranting attention. SEMS are considered highly effective for colorectal obstruction, with reported success rates exceeding 95%. However, perforation rates of up to 5% have been described^[14^]. This risk is of particular concern when barium is present in the colon. Intraperitoneal leakage of barium has historically been associated with severe chemical peritonitis, adhesions, and fibrotic granulomas, with mortality rates previously reported as high as 51%^[4,15^]. More recent reports suggest outcomes are less dire; in one series of 18 patients undergoing laparotomy for intraperitoneal barium leakage, no mortality was observed^[4^]. These finding indicate that the earlier belief of universally high mortality from “barium peritonitis” may not apply in modern practice. Nevertheless, patients should be fully informed of risk of perforation during endoscopic stent placement. Sequential high-risk interventions, such as in this case, should only be undertaken in tertiary centers with multidisciplinary expertise and immediate surgical capability.

This report has several limitations. MRI was not performed given the SEMS, limiting accurate local staging and assessment of the circumferential resection margin. We acknowledge that the absence of MRI-based R-stage evaluation is a major limitation, as it compromised the prognostic value in predicting local recurrence and guiding treatment decisions. Furthermore, the stent itself may have restricted the indication for neoadjuvant therapy, including radiotherapy and molecular-targeted agents, potentially influencing the treatment strategy and long-term outcomes.

Conclusions

This case underscores the importance of considering underlying malignancy when intestinal obstruction occurs after BMS, even in asymptomatic patients. Additionally, this case demonstrates successful minimally invasive single-stage resection and anastomosis following endoscopic stenting and clearance of retained barium causing intestinal obstruction. Further case accumulation will contribute to refining prevention and management strategies for intestinal obstruction after BMS associated with gastrointestinal malignancy.

Ethical approval

This case report was approved by the Research Ethics Committee for Life Science and Medical Research, Tohoku Medical and Pharmaceutical University (2025-4-040).

Consent

Consent for the publication of this case report with accompanying images was obtained from the patient. The consent was written in Japanese for better understanding by the patient. The consent form will be provided to the editors of this journal on request.

Sources of funding

This research did not receive any specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Author contribution

Conceptualization: T.F., S.T., Y.S. Investigation: T.F., Y.S., T.M. Data curation and visualization: Y.S., Y.K. Supervision: C.S. Project administration: C.S. Writing-original draft: T.F., S.T. Writing-review and editing: T.M., Y.K., C.S. All authors have read, commented and approved the final manuscript for submission.

Conflicts of interest disclosure

None.

Research registration unique identifying number (UIN)

Not applicable.

Guarantor

Shingo Tsujinaka.

Provenance and peer review

Not commissioned; externally peer reviewed.

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.