Differential Diagnosis for Abdominal Pain with Negative Scans
When all scans are negative, the differential diagnosis for abdominal pain can be broad and challenging. Here's a categorized approach to consider potential causes:
Single Most Likely Diagnosis
- Irritable Bowel Syndrome (IBS): This is a common condition characterized by chronic abdominal pain, bloating, and alteration of bowel habits in the absence of any mechanical, inflammatory, or biochemical abnormalities. The diagnosis is often made based on clinical criteria (Rome IV) after ruling out other causes.
Other Likely Diagnoses
- Functional Dyspepsia: Similar to IBS, functional dyspepsia involves chronic or recurrent upper abdominal pain or discomfort not explained by other pathologic conditions. It's a diagnosis of exclusion.
- Gastroesophageal Reflux Disease (GERD): Although GERD can sometimes be identified on scans, mild cases or those without significant esophageal damage might not be visible, leading to a diagnosis based on symptoms and response to treatment.
- Inflammatory Bowel Disease (IBD) in Early Stages: Early in the course of the disease, especially if the inflammation is mild or limited to areas not easily visualized by standard scans, IBD might not be immediately apparent on imaging studies.
- Adhesions or Internal Hernias: These can cause intermittent abdominal pain and might not always be visible on standard scans, requiring a high index of suspicion and sometimes more specialized imaging or diagnostic laparoscopy.
Do Not Miss Diagnoses
- Mesenteric Ischemia: This condition, which involves insufficient blood flow to the intestines, can present with nonspecific abdominal pain and may not be immediately apparent on scans, especially in the early stages. It's critical to consider this diagnosis due to its high mortality rate if untreated.
- Ectopic Pregnancy: Although typically considered in women of childbearing age with a missed period, an ectopic pregnancy can present with abdominal pain and might not be visible on all types of scans, especially if very early.
- Ovarian Torsion: This condition involves the twisting of an ovary and can cause severe abdominal pain. It's an emergency that requires prompt surgical intervention and might not be immediately diagnosed by scans if the radiologist is not alerted to consider it.
- Porphyrias: These are a group of disorders that can result in acute, severe abdominal pain without clear findings on scans. They are rare but critical to diagnose due to the potential for neurological complications and the availability of specific treatments.
Rare Diagnoses
- Chronic Intestinal Pseudo-obstruction: A rare condition characterized by impairment of the muscle contractions that move food, fluid, and air through the intestines, without any mechanical obstruction. It can cause severe abdominal pain and might not be immediately apparent on scans.
- Abdominal Migraine: A condition that presents with recurrent episodes of severe abdominal pain, often accompanied by other migraine symptoms like headache or nausea. It's more common in children but can occur in adults and might not have specific findings on scans.
- Sickle Cell Crisis: Individuals with sickle cell disease can experience acute episodes of pain, including abdominal pain, due to vaso-occlusive crises. While not all cases will have negative scans, the abdominal pain can sometimes be the predominant symptom without clear evidence of other organ involvement on imaging.