Differential Diagnosis for Severe RUQ Pain

Single Most Likely Diagnosis

• Biliary Colic or Biliary Ductal Dilatation: Given the patient's history of cholecystectomy, severe right upper quadrant (RUQ) pain could be due to biliary colic or a dilated biliary duct, possibly caused by a stone or stricture in the common bile duct.

Other Likely Diagnoses

• Hepatic Parenchymal Disease: Conditions such as hepatitis or liver abscess could cause severe RUQ pain, especially in the absence of gallbladder pathology.
• Peptic Ulcer Disease: Gastritis or peptic ulcers can cause severe upper abdominal pain, including in the RUQ, and may be exacerbated by certain medications or conditions.
• Musculoskeletal Pain: Given the patient's history of multiple vaginal births, musculoskeletal strain or issues related to the abdominal wall (e.g., rectus abdominis strain) could be a cause of RUQ pain.

Do Not Miss Diagnoses

• Hepatic Artery Aneurysm or Hepatic Artery Thrombosis: Although rare, these conditions can be life-threatening and require immediate intervention. The patient's use of Mounjaro (tirzepatide), which has been associated with an increased risk of pancreatitis and potentially other vascular events, raises the importance of considering vascular complications.
• Pancreatitis: Despite the absence of typical symptoms like vomiting and diarrhea, pancreatitis can present atypically, especially in patients with a history of cholecystectomy or those on certain medications.
• Pulmonary Embolism: While the patient denies shortness of breath (SOB), pulmonary embolism can occasionally present with chest or abdominal pain without typical respiratory symptoms, making it a "do not miss" diagnosis due to its high mortality if untreated.

Rare Diagnoses

• Hepatocellular Carcinoma or Other Liver Tumors: Although less likely without specific risk factors (e.g., cirrhosis, hepatitis B or C), liver tumors could cause RUQ pain and should be considered in the differential diagnosis, especially if other causes are ruled out.
• Intra-abdominal Shunt or Vascular Malformation: Rare vascular anomalies could cause severe abdominal pain, including in the RUQ, and might be considered if more common diagnoses are excluded.