Diagnostic Approach for Abdominal Pain

Initial Evaluation

The presence of diffuse abdominal pain with tenderness and worsening lower abdominal pain on palpation for 6 weeks warrants immediate investigation to exclude serious organic disease before attributing symptoms to a functional disorder 1
Perform baseline tests immediately, including complete blood count to assess for anemia, infection, or inflammatory markers, as recommended by the American Gastroenterological Association 2, 3
Inflammatory markers, such as C-reactive protein or erythrocyte sedimentation rate, should be used to identify inflammatory processes, according to the European Society of Gastrointestinal Endoscopy 1, 4
Serum chemistries and albumin should be evaluated to assess for metabolic derangements or malabsorption, as suggested by the American Gastroenterological Association 2, 3
Stool studies, including fecal occult blood testing, ova and parasites examination, and fecal calprotectin, should be performed to investigate gastrointestinal symptoms, as recommended by the Infectious Diseases Society of America 2, 3, 4
Celiac serology should be considered given the chronic diarrhea, according to the American College of Gastroenterology 1, 4

A CT scan of the abdomen and pelvis with oral and intravenous contrast is the most appropriate initial imaging study for diffuse abdominal pain with lower abdominal tenderness, as recommended by the American College of Radiology 5
Colonoscopy is indicated in patients with chronic diarrhea lasting 6 weeks with abdominal tenderness, as suggested by the American Society for Gastrointestinal Endoscopy 1, 6
Colonoscopy with biopsies can diagnose inflammatory bowel disease, microscopic colitis, or other mucosal pathology, according to the World Gastroenterology Organisation 2, 1

If organic disease is identified, treat the specific condition accordingly, such as inflammatory bowel disease with appropriate immunosuppression, as recommended by the European Crohn’s and Colitis Organisation 5, 6
If initial workup is negative, consider functional disorders, and use first-line treatments such as loperamide for diarrhea control and dietary modifications, as suggested by the American Gastroenterological Association 7, 6
Tricyclic antidepressants can be used for abdominal pain and global symptoms, as recommended by the American College of Gastroenterology 7, 6

Re-evaluate the patient in 3-6 weeks, and if symptoms worsen or new alarm features develop, repeat imaging and consider further endoscopic evaluation, as suggested by the American Gastroenterological Association 2, 3
Persistent symptoms despite treatment warrant referral to gastroenterology for specialized management, according to the European Society of Gastrointestinal Endoscopy 7, 6