Lower abdominal坠胀 pain is a relatively common symptom clinically.
Of course, there are many reasons for lower abdominal坠胀 pain.
In the case of men, it is mostly seen in prostatitis, prostate stones, and rectal diseases.

In the case of women, it is mostly likely to be associated with pelvic inflammatory disease and pelvic effusion, or other infections.
Of course, the possibility of a large amount of effusion in the rectouterine pouch cannot be excluded.

I suggest having an ultrasound to further confirm the diagnosis.