A 55-year-old man presents to the emergency department with nausea and vomiting for the past week. He decided to come in when his symptoms worsened. He feels that his symptoms are exacerbated with large fatty meals and when he drinks alcohol. His wife recently returned from a cruise with symptoms of vomiting and diarrhea. The patient has a medical history of poorly managed diabetes, constipation, anxiety, dyslipidemia, and hypertension. His temperature is 99.5°F (37.5°C), blood pressure is 197/128 mmHg, pulse is 100/min, respirations are 17/min, and oxygen saturation is 95% on room air. Physical exam reveals a systolic murmur heard loudest along the left upper sternal border. Abdominal exam reveals an obese, tympanitic and distended abdomen with a 3 cm scar in the right lower quadrant. Vascular exam reveals weak pulses in the lower extremities. Which of the following is the most likely underlying etiology of this patient's symptoms?
Adhesions
Enteric nervous system damage
Impacted stool
Twisting of the bowel
Adhesions
This patient is presenting with abdominal pain and a tympanitic abdomen, which are symptoms suggestive of a small bowel obstruction. In developed countries, these typically occur secondary to adhesions.

Small bowel obstructions (SBO) typically present with an absence of bowel sounds, bowel movements, and flatus, as well as abdominal distension, nausea, and vomiting. They typically occur secondary to adhesions which entrap the bowel and disrupt its normal peristalsis. Adhesions can occur after abdominal surgery or trauma as part of the normal healing process. The diagnosis of SBO can be confirmed using abdominal imaging such as a CT scan. Treatment often involves observation; however, surgical decompression of the SBO may be needed if there is a closed-loop obstruction or an obstruction that does not resolve on its own.

Rami Reddy and Cappell review the evidence regarding the diagnosis and treatment of SBO. They discuss how this disease has a 30% mortality rate if the diagnosis is missed and bowel perforation occurs. They recommend early evaluation and treatment of these patients.

Incorrect Answers:
Answer B: Enteric nervous system damage describes diabetic gastroparesis which can present similarly to SBO; however, this patient's age and history of surgery points toward SBO as the most likely diagnosis. Treatment is with pro-motility agents.

Answer C: Impacted stool describes constipation which could present similarly to SBO; however, this diagnosis is less likely to cause nausea and vomiting unless it is severe. The vomit typically smells like stool. Treatment is with dis-impaction of the colon.

Answer D: Norovirus typically causes nausea, vomiting, and diarrhea but does not cause distension and a tympanitic abdomen. Treatment is supportive as the virus self-resolves.

Answer E: Twisting of bowel describes a volvulus which presents similarly to SBO; however, it is a more common diagnosis in the elderly and is a less common diagnosis than is SBO in a patient with a history of abdominal surgery. Treatment is with surgical untwisting of the bowel.

Bullet Summary:
Small bowel obstruction (commonly caused by adhesions) presents with nausea, vomiting, absence of flatus/bowel movements, and a distended/tympanic abdomen.