What imaging study is recommended for persistent lower abdominal cramping, alternating diarrhea (initially) and constipation, and abdominal pain 2 weeks after food poisoning?

From the Guidelines

For persistent lower abdominal cramping, alternating diarrhea and constipation, and abdominal pain occurring 2 weeks after food poisoning, an abdominal CT scan with contrast is the recommended imaging study. This recommendation is based on the most recent and highest quality study available, which emphasizes the importance of imaging in evaluating patients with nonlocalizing abdominal pain 1. The CT scan provides detailed visualization of the abdominal organs, intestinal walls, and surrounding tissues, allowing for assessment of potential post-infectious complications such as irritable bowel syndrome (IBS) or post-infectious IBS.

The patient's symptoms, including persistent abdominal pain and alternating diarrhea and constipation, suggest the need for a comprehensive imaging study to rule out more serious conditions like inflammatory bowel disease, diverticulitis, or intestinal obstruction that might mimic post-infectious gastrointestinal symptoms. While ultrasound might be considered as an initial, less invasive option, particularly for evaluating the gallbladder and appendix, it provides less comprehensive information compared to a CT scan.

According to the American College of Radiology Appropriateness Criteria, CT scans are essential in evaluating patients with acute nonlocalized abdominal pain, especially when fever is present, as it raises clinical suspicion of an intra-abdominal infection or other conditions that may need immediate surgical or medical attention 1. The study also highlights the importance of imaging in the elderly and immunocompromised patients with acute abdominal pain.

In the context of post-infectious IBS, which typically develops after gastroenteritis, imaging is crucial to exclude other pathologies before settling on this diagnosis. The American Gastroenterological Association medical position statement on irritable bowel syndrome also recommends a complete physical examination, sigmoidoscopy, and additional testing, including imaging studies, when indicated 1.

Therefore, an abdominal CT scan with contrast is the most appropriate imaging study for this patient, considering the need for a detailed evaluation of the abdominal organs and surrounding tissues to rule out potential complications and guide management. The patient should be prepared to fast for several hours before the CT scan and should inform the provider about any allergies to contrast material or kidney problems.

From the Research

Imaging Studies for Abdominal Pain

The user is experiencing persistent lower abdominal cramping, alternating diarrhea (initially) and constipation, and abdominal pain 2 weeks after food poisoning. To determine the recommended imaging study, let's consider the possible causes of these symptoms.

Possible Causes

• Functional gastrointestinal disorders, such as irritable bowel syndrome (IBS) or functional abdominal pain syndrome 2
• Inflammatory bowel disease (IBD), such as Crohn's disease or ulcerative colitis 3, 4
• Other organic gastrointestinal diseases, such as biliary diseases 4

Recommended Imaging Studies

Based on the location of pain and index of suspicion for specific etiologies, the following imaging studies may be recommended:

• Computed tomography (CT) with intravenous contrast media for generalized abdominal pain, left upper quadrant pain, and lower abdominal pain 5
• Ultrasonography for right upper quadrant pain 5
• Point-of-care ultrasonography to aid in the prompt diagnosis of several etiologies of acute abdominal pain, including cholelithiasis, urolithiasis, and appendicitis 5
• Magnetic resonance imaging (MRI) if ultrasonography results are inconclusive in pregnant patients 5

Key Points to Consider

• The choice of imaging study depends on the location of pain and the suspected underlying cause 5
• A complete blood count, C-reactive protein, hepatobiliary markers, electrolytes, creatinine, glucose, urinalysis, lipase, and pregnancy testing may be recommended as part of the initial evaluation 5
• The relationship between constipation and abdominal pain is complex, and laxation may contribute to relief of pain in patients with functional constipation or IBS-C 6