Differential Diagnosis for Pancolitis and Left Sided Abdominal Pain
Single Most Likely Diagnosis
- Lactose Intolerance or Soy Milk Intolerance: The patient's symptoms occur after drinking soy milk, suggesting an intolerance or sensitivity to a component in soy milk, which could lead to gastrointestinal upset, including pancolitis and abdominal pain.
Other Likely Diagnoses
- Inflammatory Bowel Disease (IBD): Conditions like ulcerative colitis or Crohn's disease can cause pancolitis and abdominal pain. The fact that the pain is left-sided could suggest a distal or limited form of ulcerative colitis.
- Irritable Bowel Syndrome (IBS): Although IBS doesn't typically cause pancolitis, it can cause significant abdominal pain and alterations in bowel habits, which might be exacerbated by certain foods, including soy milk.
- Gastroesophageal Reflux Disease (GERD): While GERD primarily affects the upper GI tract, severe cases can lead to abdominal pain and might be exacerbated by certain foods or drinks, including soy milk.
Do Not Miss Diagnoses
- Mesenteric Ischemia: Given the patient's history of atrial fibrillation (AFib) without anticoagulation, there's a risk of embolic events, including mesenteric ischemia, which is a medical emergency. Abdominal pain out of proportion to physical examination findings is a red flag.
- Diverticulitis: Especially if the patient has a history of diverticulosis, left-sided abdominal pain could indicate diverticulitis, which requires prompt medical attention.
- Intestinal Obstruction: Although less likely, any cause of intestinal obstruction (e.g., adhesions, hernias) could present with abdominal pain and alterations in bowel habits.
Rare Diagnoses
- Eosinophilic Gastroenteritis: A rare condition characterized by eosinophilic infiltration of the gastrointestinal tract, which can cause abdominal pain, diarrhea, and other symptoms. Food intolerance, including to soy, might be a trigger.
- Microscopic Colitis: A condition causing chronic diarrhea and abdominal pain, with microscopic evidence of colonic inflammation. It might be considered if other diagnoses are ruled out and symptoms persist.
- Food Allergy or Anaphylaxis: Although rare, a severe allergic reaction to soy could cause abdominal pain among other systemic symptoms. This would be more likely if the patient has a known history of food allergies.