Differential Diagnosis
- Single Most Likely Diagnosis
- Urinary Tract Infection (UTI) or Pyelonephritis: The patient presents with penile discharge, lower abdominal pain, and urinalysis showing bacteria, which are indicative of a UTI. The presence of nausea, chills, and elevated CRP suggests a more severe infection, possibly pyelonephritis.
- Other Likely Diagnoses
- Prostatitis: The symptoms of lower abdominal pain, penile discharge, and elevated CRP could also be consistent with prostatitis, especially if the patient has a history of urinary tract issues.
- Gastroenteritis: The patient's symptoms of diarrhea, nausea, and abdominal pain could suggest a gastrointestinal infection. However, the presence of penile discharge and urinalysis results lean more towards a urinary tract issue.
- Kidney Stone: Although less likely given the absence of specific symptoms like flank pain or radiating pain, a kidney stone could cause abdominal pain and potentially lead to a UTI.
- Do Not Miss Diagnoses
- Sepsis: The patient's elevated anion gap, CRP, and symptoms like chills and nausea could indicate a severe infection leading to sepsis, which is life-threatening and requires immediate attention.
- Appendicitis: Although the abdominal X-ray shows moderate stool volume in the colon, appendicitis can sometimes present with atypical symptoms, especially in men. The lower abdominal pain and elevated CRP warrant consideration of this diagnosis.
- Rare Diagnoses
- Reiter's Syndrome (Reactive Arthritis): This condition can follow a bacterial infection and presents with symptoms like urethritis (which could explain the penile discharge), arthritis, and conjunctivitis. It's less common but should be considered if other diagnoses are ruled out.
- Tuberculosis: Although rare in many parts of the world, genitourinary tuberculosis can cause symptoms like abdominal pain, urinary frequency, and discharge. It would be considered if the patient has risk factors or if other diagnoses are excluded.