Differential Diagnosis for a 63-year-old Male with Dizziness, Vomiting, and Abdominal Pain

The patient presents with symptoms of dizziness, vomiting, inability to keep food or liquids down, and abdominal pain on the right side of the lower abdomen, alongside a history of colostomy reversal and current vital signs of 200/95 blood pressure and 97 pulse. Considering these symptoms, the differential diagnosis can be categorized as follows:

• Single Most Likely Diagnosis
  • Appendicitis: Given the location of the abdominal pain (right lower quadrant) and the history of colostomy reversal, which might not directly influence the current symptoms but is important in the surgical history, appendicitis is a strong consideration. The symptoms of vomiting, dizziness, and localized pain are consistent with appendicitis, especially in the context of potential dehydration from not being able to keep fluids down.
• Other Likely Diagnoses
  • Gastroenteritis: Although the abdominal pain is localized, gastroenteritis could cause vomiting, dizziness (from dehydration), and abdominal pain. The fact that the patient cannot keep any food or liquids down supports this possibility.
  • Intestinal Obstruction: Given the patient's history of abdominal surgery (colostomy reversal), intestinal obstruction is a plausible diagnosis. Symptoms can include vomiting, abdominal pain, and an inability to pass gas or have bowel movements.
  • Diverticulitis: This condition, which involves inflammation of the diverticula in the digestive tract, can cause abdominal pain (often on the left side but can be on the right), fever, nausea, and changes in bowel habits. While less common on the right side, it's still a consideration.
• Do Not Miss Diagnoses
  • Mesenteric Ischemia: This is a serious condition where there's a blockage in one of the major arteries that supply blood to the intestine. It can cause severe abdominal pain, vomiting, and could lead to dizziness due to pain and potential dehydration. It's critical to diagnose early as it can lead to significant morbidity and mortality if missed.
  • Ectopic Kidney or Kidney Stone: Although less likely, an ectopic kidney or a kidney stone could cause severe pain and vomiting. The location of the pain (right lower quadrant) could be consistent with these conditions, especially if the kidney is ectopically located or if a stone is passing through the ureter.
• Rare Diagnoses
  • Carcinoid Syndrome: This rare condition, often associated with neuroendocrine tumors, can cause flushing, diarrhea, wheezing, and heart valve abnormalities. While the primary symptoms don't perfectly align, the abdominal pain and vomiting could be part of a larger syndrome.
  • Inflammatory Bowel Disease (IBD) Flare: Conditions like Crohn's disease or ulcerative colitis can cause abdominal pain, vomiting, and changes in bowel habits. However, these would typically be diagnosed prior to such an acute presentation, unless this is the initial manifestation.

Labs and Tests to Order

• Complete Blood Count (CBC) to check for signs of infection or inflammation
• Basic Metabolic Panel (BMP) to assess electrolyte balance and renal function
• Liver Function Tests (LFTs) to evaluate liver health
• Lipase and amylase to rule out pancreatitis
• Urinalysis to check for urinary tract infection or kidney stones
• Imaging studies such as a CT scan of the abdomen and pelvis to evaluate for appendicitis, intestinal obstruction, diverticulitis, or other abdominal pathologies
• Consider an ECG given the patient's high blood pressure and age to evaluate cardiac status

These tests will help narrow down the differential diagnosis and guide further management in the emergency department.