Differential Diagnosis for 72-year-old with Right Iliac Fossa Pain and Bloating

Single Most Likely Diagnosis

• Diverticulitis: Given the location of the pain (right iliac fossa) and the age of the patient, diverticulitis is a strong consideration, especially if the patient has a history of diverticulosis. However, the classic presentation of diverticulitis usually involves left lower quadrant pain, but right-sided diverticulitis can occur, especially in Asian populations.

Other Likely Diagnoses

• Appendicitis: Although appendicitis is more common in younger populations, it can occur at any age. The presentation of appendicitis typically involves pain that initially is diffuse or around the navel and then localizes to the right lower quadrant.
• Irritable Bowel Syndrome (IBS): IBS could be a consideration given the bloating and abdominal pain, but the localized nature of the pain to the right iliac fossa might be less typical for IBS.
• Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease or ulcerative colitis can present with chronic abdominal pain, bloating, and changes in bowel habits. The right lower quadrant pain could be consistent with Crohn's disease involving the terminal ileum.

Do Not Miss Diagnoses

• Colon Cancer: Right-sided colon cancer can present with abdominal pain, bloating, and changes in bowel habits. It's crucial to consider this diagnosis, especially in an elderly patient, due to the potential for significant morbidity and mortality if missed.
• Intestinal Obstruction: Although less common, an obstruction in the small intestine could cause right lower quadrant pain and bloating. This condition requires prompt diagnosis and treatment to prevent complications.
• Mesenteric Ischemia: This is a vascular emergency that can present with severe abdominal pain out of proportion to the physical examination findings. It's more common in older patients with vascular disease.

Rare Diagnoses

• Carcinoid Tumor: These neuroendocrine tumors can arise in the small intestine and present with abdominal pain, bloating, and other non-specific symptoms.
• Meckel's Diverticulum: A congenital anomaly of the small intestine that can cause pain, especially if it becomes inflamed or if there is a complication like intestinal obstruction or bleeding.
• Right Ovarian Torsion or Cyst: Although less common in post-menopausal women, ovarian pathology can still occur and cause right lower quadrant pain.