Spontaneous intramural small bowel hematoma: unusual cause of intestinal subocclusion in an anticoagulated patient—a case report

Introduction

Spontaneous intramural small bowel hematoma (SISBH) is a rare complication of excessive oral anticoagulation. It generally presents with acute abdominal symptoms, ranging from mild abdominal pain to resembling acute abdomen. SISBH more commonly occurs as a complication of long-term anticoagulation with vitamin K antagonists (VKAs), particularly warfarin. Nevertheless, SISBH remains understudied and underdiagnosed. Despite being first described in 1952 and having an estimated incidence of approximately 1 in 2,500 patients, a recent systematic review of English-language literature identified only 34 reports on SISBH secondary to warfarin, encompassing 39 patients (1-3). In this article, we describe an additional SISBH case, contributing to the still limited existing literature, and provide the first report of total-body positron emission tomography/computed tomography (PET/CT) scan use in the diagnostic workup of this condition. This report highlights the clinical presentation, diagnostic challenges and management strategies for SISBH. We present this article in accordance with the CARE reporting checklist (available at https://acr.amegroups.com/article/view/10.21037/acr-2025-108/rc).

Case presentation

A 53-year-old male presented to the emergency department for nausea and sudden-onset, constant abdominal pain that had lasted for 30 hours, predominantly in the mesogastric region and rated as a 7 out of 10 on the pain scale. He also reported abdominal distension and a 3-day history of obstipation. Physical examination showed abdominal distension, increased bowel sounds and rebound tenderness. The patient’s medical history was significant for rheumatic heart disease-associated atrial fibrillation, with a mechanical mitral valve replacement 24 years earlier. He was on long-term oral anticoagulation with warfarin (5 mg, once daily), carvedilol (25 mg, twice daily) and enalapril (10 mg, twice daily).

Coagulation testing, a complete blood count, and an abdominal CT scan were ordered. Laboratory tests showed a markedly elevated international normalized ratio (INR) of 8.3, hemoglobin level of 15.5 g/dL and platelet count of 201,000/mm³. Abdominal imaging revealed diffuse jejunal parietal thickening (Figure 1).

Figure 1 Abdominal CT. Arrow points to jejunal parietal thickening. CT, computed tomography.

The next day, the patient’s nausea and abdominal pain persisted and were accompanied by vomiting, hematochezia, and hematuria (Table 1), in addition to a normal bowel movement. Given the intestinal thickening, a lymphoproliferative neoplastic process associated with a jejunal hematoma was considered as a differential diagnosis. To rule out this possibility, a total-body PET/CT scan was performed. The images were consistent with jejunal parietal thickening, with increased glycolytic metabolism suggestive of hematoma or an inflammatory process; however, a neoplastic process could not be definitively ruled out (Figure 2).

Figure 2 Total-body PET/CT. Circles show jejunal parietal thickening, with increased glycolytic metabolism, suggestive of hematoma or an inflammatory process. PET/CT, positron emission tomography/computed tomography.

Based on these findings, the hypothesis of SISBH secondary to warfarin intoxication was raised. The patient was evaluated by the surgical team and surgery was deemed contraindicated. We opted for a conservative management approach for warfarin poisoning, which consisted of temporary warfarin suspension, intravenous hydration and vitamin K infusion. INR and hemoglobin measurements were used for monitoring (Table 2). Once the INR reached 1.8, full anticoagulation with enoxaparin 1 mg/kg was initiated, and warfarin was gradually reintroduced to achieve optimal INR for patients with mechanical mitral valve prostheses.

On the third day of hospitalization, nausea persisted but abdominal pain subsided. He remained asymptomatic until the fifth hospitalization day, when he presented nausea, vomiting and melena, but no hemodynamic instability was observed. Gastrointestinal symptoms resolved on the following day, but he developed cough and odynophagia, which lasted for three days. He tested negative for coronavirus disease 2019 (COVID-19).

On the ninth hospitalization day, the patient was asymptomatic and was discharged from the hospital. He was prescribed carvedilol (25 mg, twice daily), enalapril (10 mg, twice daily), warfarin (5 mg from Monday to Thursday and 2.5 mg from Friday to Sunday), and enoxaparin (60 mg, twice daily) for seven days. The patient was assessed in an outpatient visit one month later and had recovered fully. A summary of the sequence of events in this case can be found in Figure 3.

Figure 3 Case report timeline. INR, international normalized ratio; PET/CT, positron emission tomography/computed tomography.

All procedures performed in this case were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Declaration of Helsinki and its subsequent amendments. Written informed consent for publication of this case report and accompanying images was not obtained from the patient or the relatives after all possible attempts were made.

Discussion

Oral anticoagulants are widely used for treatment and prophylaxis of thrombotic and thromboembolic events. Despite increased direct oral anticoagulants (DOACs) use in recent years, the most prevalent oral anticoagulants remain VKA, particularly warfarin, due to its low cost and superior efficacy in patients with mechanical valve prostheses and patients with rheumatic heart disease-associated atrial fibrillation (4-6).

VKAs have narrower therapeutic windows compared with DOACs, requiring strict therapeutic monitoring through frequent measurement of coagulation parameters, notably INR, to prevent hemorrhagic or thromboembolic complications. Achieving and maintaining optimal INR levels is challenging for patients, especially those with lower socioeconomic status (7,8).

Nonetheless, effective SISBH prevention relies on careful VKA anticoagulation management, including maintaining the INR within therapeutic range, regular monitoring and early identification of high-risk patients, especially those exhibiting traditional risk factors, including male sex, age above 60 years, and hypertension (2,3,9).

SISBH presentation is usually acute abdominal pain, often accompanied by nausea and vomiting, and occasionally gastrointestinal bleeding (10). Jejunum is the most commonly affected site, followed by ileum and duodenum (11). To avoid unnecessary procedures, SISBH should be considered in patients on anticoagulation therapy with abdominal pain. A high index of suspicion, followed by prompt imaging, is key to early diagnosis.

Abdominal CT is the preferred imaging method for SISBH diagnosis, as it has high sensitivity and can reveal hematoma-related changes in nearly 100% of cases (9). The most frequent CT findings, despite being nonspecific, include wall thickening, mural hyperdensity, and luminal narrowing (11,12). In our case, while PET/CT results were consistent with a hematoma, the scan’s inability to rule out an important differential diagnosis, such as a neoplastic process, meant it provided minimal diagnostic value beyond an abdominal CT.

SISBH is generally a benign condition, with symptoms resolving after INR normalization. This is achieved by temporary warfarin suspension, combined with vitamin K replacement, or prothrombin complex concentrate administration, or transfusion of fresh frozen plasma, if necessary. In these cases, the symptoms typically resolve in 5 to 7 days (13).

Nonetheless, due to its non-specific symptoms, SISBH poses a diagnostic challenge and can be mistaken for an acute abdomen, leading to unnecessary invasive treatments (9). Surgical intervention should only be considered when there is robust evidence of active intestinal bleeding or an acute abdomen resulting from hematoma-induced obstruction and ischemia (10,14).

This clinical case report highlights the relevance of SISBH as a differential diagnosis for acute abdominal symptoms in patients on long-term anticoagulation therapy with VKAs. The symptoms at presentation may be nonspecific; yet, considering the widespread use of VKAs, this complication must be known by clinicians attending to these patients.

As a case report, our paper has several important limitations. The absence of multiple patients and a control group precludes comparisons with alternative management strategies. Furthermore, the lack of long-term follow-up data and recurrence rates restricts the ability to assess sustained outcomes or to derive evidence-based clinical recommendations. Finally, the present study has limited external validity, and its findings should not be extrapolated to broader patient populations.

Conclusions

SISBH, although rare, should be considered in the differential diagnosis of acute abdominal symptoms in patients receiving long-term oral anticoagulation, particularly with VKAs. A high index of suspicion, followed by prompt abdominal CT, is key to early diagnosis. Conservative management, which entails anticoagulation reversal and supportive care, is generally the primary therapeutic strategy adopted in the literature, demonstrating favorable short-term outcomes, as was the case with our patient.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the CARE reporting checklist. Available at https://acr.amegroups.com/article/view/10.21037/acr-2025-108/rc

Peer Review File: Available at https://acr.amegroups.com/article/view/10.21037/acr-2025-108/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://acr.amegroups.com/article/view/10.21037/acr-2025-108/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All procedures performed in this case were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Declaration of Helsinki and its subsequent amendments. Written informed consent for publication of this case report and accompanying images was not obtained from the patient or the relatives after all possible attempts were made.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. BERMAN H. MAINELLA FS. Toxic results of anticoagulant therapy. N Y State J Med 1952;52:725-7.
2. Bettler S, Montani S, Bachmann F. Schweiz Med Wochenschr 1983;113:630-6. [Incidence of intramural digestive system hematoma in anticoagulation Epidemiologic study and clinical aspects of 59 cases observed in Switzerland (1970-1975)].
3. Wang Z, Jiang T, Mu M, et al. Small bowel intramural hematoma caused by warfarin: case report and literature review. Scand J Gastroenterol 2024;59:763-9. [Crossref] [PubMed]
4. Colacci M, Tseng EK, Sacks CA, et al. Oral Anticoagulant Utilization in the United States and United Kingdom. J Gen Intern Med 2020;35:2505-7. [Crossref] [PubMed]
5. Eikelboom JW, Connolly SJ, Brueckmann M, et al. Dabigatran versus warfarin in patients with mechanical heart valves. N Engl J Med 2013;369:1206-14. [Crossref] [PubMed]
6. Connolly SJ, Karthikeyan G, Ntsekhe M, et al. Rivaroxaban in Rheumatic Heart Disease-Associated Atrial Fibrillation. N Engl J Med 2022;387:978-88. [Crossref] [PubMed]
7. Esmerio FG, Souza EN, Leiria TL, et al. Constant use of oral anticoagulants: implications in the control of their adequate levels. Arq Bras Cardiol 2009;93:549-54. [Crossref] [PubMed]
8. Malagutte KNDS, Silveira CFDSMPD, Reis FM, et al. Quality of Oral Anticoagulation in Atrial Fibrillation Patients at a Tertiary Hospital in Brazil. Qualidade da Anticoagulação Oral em Pacientes com Fibrilação Atrial em um Hospital Terciário no Brasil. Arq Bras Cardiol 2022;119:363-9. [Crossref] [PubMed]
9. Sorbello MP, Utiyama EM, Parreira JG, et al. Spontaneous intramural small bowel hematoma induced by anticoagulant therapy: review and case report. Clinics (Sao Paulo) 2007;62:785-90. [Crossref] [PubMed]
10. Uzun MA, Koksal N, Gunerhan Y, et al. Intestinal obstruction due to spontaneous intramural hematoma of the small intestine during warfarin use: a report of two cases. Eur J Emerg Med 2007;14:272-3. [Crossref] [PubMed]
11. Abbas MA, Collins JM, Olden KW. Spontaneous intramural small-bowel hematoma: imaging findings and outcome. AJR Am J Roentgenol 2002;179:1389-94. [Crossref] [PubMed]
12. Hajihashemi A, Khanifar H, Geravandi M. Spontaneous intramural hematoma of the small bowel in anticoagulated patients-Insights into management: A case report. Radiol Case Rep 2025;20:5189-95. [Crossref] [PubMed]
13. Yoldaş T, Erol V, Çalışkan C, et al. Spontaneous intestinal intramural hematoma: What to do and not to do. Ulus Cerrahi Derg 2013;29:72-5. [Crossref] [PubMed]
14. Abreu da Silva A, Amaro C, Sousa D. Small Bowel Obstruction Secondary to a Spontaneous Intramural Jejunal Hematoma. Acta Med Port 2024;37:296-7. [Crossref] [PubMed]