Differential Diagnosis for Acute on Chronic Abdominal Pain
Single Most Likely Diagnosis
- Chronic Intestinal Pseudo-Obstruction: Given the history of low-grade ileus and constipation, this condition is a strong candidate. It involves impaired intestinal motility leading to recurrent episodes of abdominal pain, nausea, vomiting, and constipation, which aligns with the patient's symptoms.
Other Likely Diagnoses
- Adhesional Small Bowel Obstruction: Previous abdominal surgeries or infections can lead to adhesions, which may cause intermittent or chronic bowel obstruction, presenting with abdominal pain, constipation, and possibly a history of low-grade ileus.
- Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease or ulcerative colitis can cause chronic abdominal pain, changes in bowel habits (including constipation), and may have been exacerbated by a previous ileus, leading to an acute on chronic presentation.
- Irritable Bowel Syndrome (IBS): Although IBS is more commonly associated with chronic symptoms, an acute exacerbation could present as acute on chronic abdominal pain, especially if there's a history of constipation-predominant IBS.
Do Not Miss Diagnoses
- Mesenteric Ischemia: This is a potentially life-threatening condition that could present with acute abdominal pain, even in the context of chronic symptoms. Previous ileus or constipation might not directly relate, but missing this diagnosis could be fatal.
- Appendicitis or Other Acute Abdominal Emergencies: Even though the patient has chronic symptoms, it's crucial not to overlook the possibility of an acute appendicitis or other emergencies like a perforated viscus, especially if the acute pain represents a significant change from the patient's baseline.
- Ovarian Torsion: In female patients, ovarian torsion is a surgical emergency that can present with acute abdominal pain and might be overlooked in the context of chronic symptoms.
Rare Diagnoses
- Intestinal Lymphoma: Although rare, lymphoma can cause chronic abdominal symptoms, including pain and changes in bowel habits. An acute exacerbation could be mistaken for other, more common conditions.
- Chronic Intestinal Ischemia: This condition can lead to chronic abdominal pain and changes in bowel habits due to insufficient blood flow to the intestines. It's less common but should be considered, especially in patients with risk factors for vascular disease.
- Neurological Disorders (e.g., Abdominal Migraine, Porphyria): Certain neurological conditions can cause recurrent episodes of severe abdominal pain, which might be acute on chronic, along with other symptoms like constipation. These are less common but important to consider in the differential diagnosis.