A 37-year-old man comes to the emergency department due to 2 days of progressive, colicky abdominal pain, abdominal distension, nausea, and vomiting. He had a similar episode 2 years ago that resolved spontaneously and did not require medical attention. He has no chronic medical conditions. Temperature is 36.8 C (98.2 F), blood pressure is 122/80 mm Hg, and pulse is 92/min. The abdomen is distended and tender without rigidity or guarding. Abdominal x-ray is shown in the image below: Which of the following is the most likely diagnosis?

Question

A 37-year-old man comes to the emergency department due to 2 days of progressive, colicky abdominal pain, abdominal distension, nausea, and vomiting.  He had a similar episode 2 years ago that resolved spontaneously and did not require medical attention.  He has no chronic medical conditions.  Temperature is 36.8 C (98.2 F), blood pressure is 122/80 mm Hg, and pulse is 92/min.  The abdomen is distended and tender without rigidity or guarding.  Abdominal x-ray is shown in the image below:  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

11ec25c8_d840_b9f2_bc81_039ca6238531_MD0003_00 This patient with progressive abdominal pain, distension, and a single, dilated loop of large bowel on x-ray most likely has colonic volvulus. Cecal volvulus is the second most common form of colonic volvulus (after sigmoid volvulus) and occurs when the cecum and ascending colon twist on their mesentery. Although constipation and advanced age are risk factors for both types of volvulus, patients with cecal volvulus tend to be younger and often report prior self-resolving episodes because many have a congenital mobile cecum (ie, mesentery failed to fuse with the parietal peritoneum). Cecal volvulus forms a closed-loop obstruction. With continued gas formation by intraluminal bacteria, the lumen of the obstructed bowel loop gradually expands. This leads to slowly progressive (eg, over 2 days) abdominal distension and discomfort frequently accompanied by nausea and vomiting. As in this patient, abdominal x-ray may reveal a large, dilated colonic loop. However, plain radiographs are diagnostic less often in cecal than in sigmoid volvulus, so abdominopelvic CT scan is typically performed. abdominopelvic CT scan Treatment is emergency laparotomy and resection of the volvulized colonic segment (eg, right colectomy). Endoscopic detorsion is not advised (success rate: <5%-20%). This contrasts with the management of sigmoid volvulus, in which endoscopic detorsion is the first-line treatment (success rate: >75%-90%) prior to elective, rather than emergency, sigmoid colectomy. (Choice B) Gastric outlet obstruction (eg, due to malignancy) can cause abdominal distension and pain; however, x-ray typically reveals an enlarged gastric bubble with decompressed bowel distally. enlarged gastric bubble (Choice C) Ileocolic intussusception (prolapse of the ileum into the colon) can cause self-resolving episodes of abdominal pain and vomiting. However, because the mechanical obstruction occurs in the distal small bowel (ie, ileum), x-ray typically reveals multiple, dilated small-bowel loops with air-fluid levels. dilated small-bowel loops with air-fluid levels (Choice D) Paralytic ileus (intestinal obstruction due to dysfunctional peristalsis) typically causes generalized distension of the large and small bowel on x-ray. generalized distension of the large and small bowel (Choice E) Toxic megacolon can cause colonic dilation on x-ray. However, x-ray typically reveals diffuse dilation of the colon within its normal anatomic arrangement rather than a single, dilated colonic loop, as in cecal volvulus. In addition, patients typically appear toxic (eg, fever, altered sensorium) and often have bloody diarrhea. diffuse dilation of the colon Educational objective: Cecal volvulus occurs when the cecum and ascending colon twist on their mesentery, forming a closed-loop obstruction. Progressive abdominal pain and distension, along with nausea/vomiting, are typical. Abdominal x-ray may reveal a large, dilated loop of colon. References: Volvulus. (http://www.ncbi.nlm.nih.gov/pubmed/30243456)

A 37-Year-Old Man Comes to the Emergency Department Due to 2