(P40) Detorsing a Hidden Small Bowel Obstruction

Chief Complaint : Abdominal Pain, and nausea for 1 day

History of Present Illness : 33-year-old female G2P1011 (1 c-section, 1 surgical abortion) with PMH of fibroids presents with acute onset abdominal pain for 1 day. Last night, she went out with friends and had a couple of drinks. She was in her usual state of health. This morning, she started having cramping lower abdominal pain which started periumbilical and moved into her right pelvic region. Pain is episodic, with periods of mild pain in between minutes of more intense pain lasting for five to ten minutes each time. Pain was associated with nausea and urinary urgency, but without vomiting. Denies dysuria, hematuria, vaginal bleeding, or discharge. Her last bowel movement was this morning, normal in color and consistency. Last menstrual period was the month prior to presentation. Sexual history notable for being sexually active with one male partner without contraception. Of note, she has a remote history of chlamydia which was treated with antibiotics.

Pertinent Physical Exam: On initial assessment, vital signs were notable for BP 110/78 and heart rate of 95. Patient was afebrile with normal respiratory rate and oxygen saturation. Initial exam was notable for our patient with lower abdominal tenderness, appearing uncomfortable.
Upon reassessment, patient was pale and had a blood pressure of 70/40 responsive to fluids. She now feels light-headed and appears diaphoretic. Patient now writhing in pain with guarding to the right lower quadrant. External genital exam was unremarkable. Speculum and bimanual exam were deferred secondary to patient’s pain level. Urine pregnancy negative.

Pertinent Laboratory Data: FAST showed no free fluid in RUQ, LUQ. Suprapubic views were technically challenging. TVUS showed a large, irregularly-shaped anechoic structure surrounded by a hyperechoic border immediately adjacent to the left ovary (Figure 1 and 2).
CT imaging showed questionable pelvic hematoma measuring 7.4 x 5.6 cm. Gynecology was consulted for ovarian torsion and our patient went to the OR for diagnostic laparoscopy.
Intra-operatively, small bowel strangulation was noted due to a single adhesive band 2 centimeters away from the Terminal Ileum. The small bowel appeared hemorrhagic, without any signs of necrosis and was released without complication (Figure 3).

Case Discussion: One of the most common complaints in the emergency room is right lower abdominal pain, especially in young women. Upon initial assessment of our patient, our differential diagnosis included: ovarian torsion, ectopic pregnancy, tubo-ovarian abscess, appendicitis, UTI, pyelonephritis, and nephrolithiasis. Given how her pain acutely fluctuated throughout her ED course, ovarian torsion was the most concerning differential that required timely diagnosis and immediate intervention.
In instances where young female patients are showing frank signs of serious intraabdominal pathology, having access to and being able to interpret transvaginal POCUS in the emergency department is vital to ruling out critical diagnoses in a timely manner. It may also be helpful in identifying pathology which is non-emergent, but requires prompt gynecological follow-up such as malignancy, ovarian cysts, hydrosalpinx, and endometrioma (1).
Small bowel obstruction, especially in young patients without significant surgical or cancer history, is not typically included in the ER differential for abdominal pain. The finding of a small bowel obstruction in a young female with only a surgical history of c-section is extremely rare (0.1%) (2). However, there have been case reports citing leiomyoma (3), endometriosis (4), and lupus (5) causing SBO as well.
The presenting features of a small bowel obstruction vary, but typically involve prior abdominal surgery, constipation, and abdominal distension. Signs that are concerning for strangulation include fever, hypotension, diffuse abdominal pain, and peritonitis. Diagnosis is made with imaging such as computed tomography or ultrasound (6). However, in this case, neither was conclusive to make a diagnosis.
This case emphasizes the importance of a high suspicion and prompt recognition of potentially detrimental pathology through frequent reassessments, especially with change in vital signs. Repeating the physical exam was key in identifying our patient’s acute abdomen and need for further intervention.

References and Acknowledgements (Optional): 1. M. Stumpf, C. Tibbles. Pelvic ultrasonography in the emergency evaluation of nonpregnant patients with pelvic pain or vaginal bleeding. Annals of Emergency Medicine, Volume 44, Issue 4, Supplement, 2004, Page S113, ISSN 0196-0644. https://doi.org/10.1016/j.annemergmed.2004.07.368.
2. Di Buono G, Ricupati F, Maienza E, Gulotta L, Buscemi S, Agrusa A. Small bowel obstruction after caesarean section: Laparoscopic management. Two case reports. Int J Surg Case Rep. 2020;77S(Suppl):S96-S100. doi: 10.1016/j.ijscr.2020.09.059. Epub 2020 Sep 14. PMID: 32972893; PMCID: PMC7876740.
3. Hughes J, Lee A, Fong J, Vazquez M, Wright D, Bui A. Leiomyoma: a rare cause of small bowel obstruction. ANZ J Surg. 2020 Jun;90(6):1165-1168. doi: 10.1111/ans.15698. Epub 2020 Jan 17. PMID: 31951072.
4. Lam K, Lang E. Endometriosis as a rare cause of small bowel obstruction. ANZ J Surg. 2020 Nov;90(11):E137-E138. doi: 10.1111/ans.15916. Epub 2020 Apr 27. PMID: 32339367.
5. Yang Y, Bartsch AM, Fryer E, Hancu D. Lupus causing small bowel obstruction. BMJ Case Rep. 2018 Sep 27;2018:bcr2018225886. doi: 10.1136/bcr-2018-225886. PMID: 30262532; PMCID: PMC6169646.
6. Long B, Robertson J, Koyfman A. Emergency Medicine Evaluation and Management of Small Bowel Obstruction: Evidence-Based Recommendations. J Emerg Med. 2019 Feb;56(2):166-176. doi: 10.1016/j.jemermed.2018.10.024. Epub 2018 Dec 6. PMID: 30527563.