**Conflict of interest**

**Figure 16.** Case of small bowel obstruction evident by dilated (> 2.5–3 cm) fluid-filled small bowel loops and increased peristalsis of the dilated segment, as evidenced by the to-and-fro or whirling motion of the bowel contents (Video\*

Small bowel obstruction (SBO) is a common cause of acute abdomen. It accounts for about 2% of patients presenting to ED with abdominal pain [95]. CT with contrast is considered to be the gold standard for the diagnosis of SBO as it has high sensitivity and specificity for the diagnosis [96–98]. It can often determine the location, cause, and complications related to bowel obstruction [99]. However, due to its cost and radiation, it is not the ideal initial imaging modality of choice in all suspected cases. Abdominal X-ray (AXR) is typically considered the initial imaging modality of choice in all suspected cases of SBO presenting to the ED. In recent years, POCUS has been utilized as a screening imaging modality for suspected cases of SBO (**Figure 16**). POCUS is more accurate, more sensitive, and more specific than AXR [95, 100, 101].

Patients present to the ED with a variety of ocular emergencies, ranging from simple conjunctivitis to sight-threatening diseases. The challenge lies in the assessment of such emergencies due to limited equipment availability and physician training; moreover, ophthalmology consultation is not available in all settings. This may place considerable burden on the EP to make

Ocular ultrasound can non-invasively diagnose retinal detachment with high sensitivity (**Figure 17**) [103], vitreous hemorrhage/detachment [104], globe rupture, and lens dislocation [105]. Measurement of optic nerve sheet diameter has been shown to correlate with increased

**2.11. Bowel ultrasound**

134 Essentials of Accident and Emergency Medicine

**2.12. Ocular ultrasound**

a rapid decision [102].

intracranial pressure [106].

06).

All authors declare to have no conflict of interest.
