What testing is recommended for a 33-year-old patient with new onset constipation and abdominal pain for 12 months?

From the Guidelines

For a 33-year-old patient with new onset constipation and abdominal pain for 12 months, a complete blood count is the only necessary initial test, unless other clinical features warrant otherwise, as recommended by the American Gastroenterological Association 1. The patient's symptoms of new onset constipation and abdominal pain for 12 months require a thorough evaluation to rule out underlying medical causes.

Initial Evaluation

• A detailed history and physical examination should be performed to identify any alarm features such as blood in stools, anemia, or weight loss.
• Basic laboratory tests, including a complete blood count, should be done as recommended by the American Gastroenterological Association 1.

Further Testing

• Metabolic tests, such as glucose, calcium, and sensitive thyroid-stimulating hormone, are not recommended unless other clinical features warrant otherwise, as stated by the American Gastroenterological Association 1.
• A colonoscopy should not be performed unless the patient has alarm features or has not undergone age-appropriate colon cancer screening, as recommended by the American Gastroenterological Association 1 and supported by the British Society of Gastroenterology guidelines on the management of irritable bowel syndrome 1.
• Additional testing, such as anorectal manometry and defecography, may be considered if there is suspicion of pelvic floor dysfunction, but only after initial evaluations have been completed. It is essential to note that the British Society of Gastroenterology guidelines on the management of irritable bowel syndrome 1 emphasize the importance of establishing an effective doctor-patient relationship and a shared understanding in the management of IBS, which can lead to improved quality of life and symptoms. However, the most recent and highest quality study, which is the 2021 British Society of Gastroenterology guidelines on the management of irritable bowel syndrome 1, recommends that all patients presenting with symptoms of IBS for the first time in primary care should have a full blood count, C reactive protein or erythrocyte sedimentation rate, coeliac serology, and, in patients <45 years of age with diarrhoea, a faecal calprotectin to exclude inflammatory bowel disease. Therefore, the initial testing for this patient should include a complete blood count, as recommended by the American Gastroenterological Association 1, and other tests as recommended by the British Society of Gastroenterology guidelines on the management of irritable bowel syndrome 1.

From the FDA Drug Label

Patients presenting with complaints of constipation should have a thorough medical history and physical examination to detect associated metabolic, endocrine and neurogenic conditions and medications. A diagnostic evaluation should include a structural examination of the colon The recommended testing for a 33-year-old patient with new onset constipation and abdominal pain for 12 months includes:

• A thorough medical history and physical examination to detect associated conditions and medications
• A structural examination of the colon 2

From the Research

Evaluation of Constipation and Abdominal Pain

To evaluate a 33-year-old patient with new onset constipation and abdominal pain for 12 months, the following tests are recommended:

• A complete history and physical examination to elicit the cause of constipation and abdominal pain 3
• Laboratory tests such as complete blood count, electrolytes, and liver function tests to rule out underlying conditions 4
• Colonic transit study to diagnose slow transit constipation 3, 5
• Anorectal manometry, defecography, and electromyography to evaluate obstructive defecation 3, 5
• Balloon expulsion test to assess pelvic floor dysfunction 4

Ruling Out Organic Causes

It is essential to rule out organic causes of constipation and abdominal pain, such as malignancy, before making a diagnosis of functional constipation 3.

• Imaging studies such as computed tomography or ultrasonography may be necessary to rule out conditions like cholelithiasis, urolithiasis, or diverticulitis 6
• Endoscopy may be considered if there are alarm features such as weight loss, bleeding, or anemia 7, 4

Diagnostic Approach

The diagnostic approach should be guided by the patient's symptoms, medical history, and physical examination findings 5, 6.

• A systematic review of diagnostic tests for constipation in adults found that colonic transit, anorectal manometry, and balloon expulsion tests reveal physiologic abnormalities in many patients with constipation 4
• However, no single test adequately defines the pathophysiology of constipation, and a combination of tests may be necessary to establish a diagnosis 4