A 68-year-old man with a history of colorectal cancer presents to the emergency department with acute onset abdominal distension, vomiting, and colicky pain. Plain abdominal radiograph shows a "coffee bean" sign with transition zone in the left lower abdomen. What is the most appropriate immediate next step in management?

Explanation

## Clinical Scenario Analysis The patient presents with classic features of **sigmoid volvulus**: - "Coffee bean" sign on plain radiograph (pathognomonic twisted loop appearance) - Transition zone in left lower abdomen - Acute colicky obstruction with vomiting ## Management Approach for Sigmoid Volvulus **Key Point:** Sigmoid volvulus is a surgical emergency when there is evidence of complete obstruction with transition zone and risk of ischemia. ### Immediate Management Steps 1. **Nasogastric (NG) tube insertion** — decompresses proximal bowel, reduces aspiration risk 2. **IV fluid resuscitation** — corrects hypovolemia and electrolyte abnormalities from vomiting 3. **Urgent surgical consultation** — volvulus with transition zone suggests complete obstruction; risk of perforation and gangrene is high **Clinical Pearl:** While rectal tube decompression (Flatus tube) may be attempted in some cases of uncomplicated sigmoid volvulus, the presence of a clear transition zone on plain radiograph indicates mechanical obstruction that typically requires surgical intervention. Delayed management increases risk of bowel necrosis and perforation. **High-Yield:** The "coffee bean" sign is virtually pathognomonic for volvulus; when combined with transition zone, it indicates complete obstruction and warrants urgent surgical evaluation. ### Why Not Proceed Directly to Laparotomy? While surgery is ultimately needed, immediate resuscitation and NG decompression are critical to: - Optimize hemodynamics - Reduce aspiration risk - Allow surgical team to prepare - Assess for signs of perforation or peritonitis ### Role of CT in This Context CT is useful for **equivocal cases** or to assess for complications (perforation, ischemia), but is **not mandatory** when plain film diagnosis is clear and surgical consultation is already engaged. Delays in surgery increase morbidity. ```mermaid flowchart TD A["Acute abdominal distension + vomiting"]:::outcome --> B{"Plain film shows transition zone?"}:::decision B -->|"Yes: Coffee bean sign"| C["Complete obstruction suspected"]:::outcome C --> D["NG tube + IV fluids"]:::action D --> E["Urgent surgical consultation"]:::action E --> F{"Signs of perforation/peritonitis?"}:::decision F -->|"Yes"| G["Emergency laparotomy"]:::urgent F -->|"No"| H["Assess for rectal decompression attempt"]:::action H --> I{"Decompression successful?"}:::decision I -->|"No"| J["Proceed to surgery"]:::action I -->|"Yes"| K["Observe, repeat imaging"]:::action ```