Final answer:
The 40-year-old man's symptoms suggest a possible Urinary Tract Infection (UTI), particularly given his medical history of prostatitis. A urinalysis and a possible prescription for antibiotics would be the next investigative steps by his physician. Other potential diagnoses like kidney stones or diabetes mellitus are less likely but may require further evaluation if symptoms persist.
Step-by-step explanation:
Potential Diagnosis and Next Steps
The symptoms presented by the 40-year-old man, which include frequent urination, urgency, and pain during urination, as well as tenderness in the lower abdomen and lower back, could be indicative of several conditions. The potential diagnosis for these symptoms could be a Urinary Tract Infection (UTI). Given his past medical history of prostatitis, there is a likelihood that he may have difficulty fully emptying his bladder, which can predispose him to UTI. This condition is often characterized by symptoms such as a burning feeling when urinating, frequent or intense urges to urinate, pain in the back or side, cloudy or bloody urine, and fever or chills.
Considering the symptoms, the recommended next steps would likely include a urinalysis to check for the presence of bacteria, white blood cells, or red blood cells, which can indicate an infection. Depending on the results, the physician may prescribe antibiotics. Additionally, a focused assessment of his prostate through a digital rectal exam could provide insights, given his history of prostatitis.
Kidney stones and diabetes mellitus are less likely due to the absence of symptoms such as severe colicky pain (for kidney stones) or polyuria and polydipsia (for diabetes). However, if his symptoms do not improve with treatment for a UTI, further evaluation for these conditions may be necessary.