Differential Diagnosis for Abdominal Pain with Normal CTAP
Single Most Likely Diagnosis
- Functional abdominal pain: This is a common cause of abdominal pain without an identifiable organic cause, which would explain the normal CTAP findings. It encompasses various conditions such as irritable bowel syndrome (IBS), functional dyspepsia, and abdominal migraine.
Other Likely Diagnoses
- Gastroesophageal reflux disease (GERD): Although CTAP might not show direct evidence of GERD, it can cause significant abdominal pain. The diagnosis is often made clinically and with the help of other diagnostic tools like endoscopy or pH monitoring.
- Peptic ulcer disease: Early or small ulcers might not be visible on CTAP, and the patient could still experience significant pain.
- Inflammatory bowel disease (IBD): Early stages of IBD, such as Crohn's disease or ulcerative colitis, might not have characteristic findings on CTAP, especially if the disease is limited to the mucosa.
Do Not Miss Diagnoses
- Mesenteric ischemia: This condition can present with non-specific abdominal pain and might have a normal CTAP if the ischemia is intermittent or not severe enough to cause infarction. It's crucial to consider this diagnosis due to its high mortality rate if missed.
- Ovarian torsion: Although more common in women, ovarian torsion can occur in anyone with ovaries and can present with severe abdominal pain. CTAP might not always show the torsion, especially if it's intermittent.
- Ectopic pregnancy: In early stages, an ectopic pregnancy might not be visible on CTAP, but it's a critical diagnosis to consider due to its potential for severe consequences, including death.
Rare Diagnoses
- Chronic intestinal pseudo-obstruction: A rare condition characterized by recurrent episodes of abdominal pain and signs of intestinal obstruction without any mechanical obstruction. CTAP might appear normal between episodes.
- Abdominal epilepsy: A rare condition where abdominal pain is a manifestation of seizure activity. Diagnostic tests like CTAP would typically be normal.
- Porphyrias: A group of rare genetic disorders that can cause acute intermittent porphyria, leading to severe abdominal pain without specific findings on CTAP.