The day after intercourse, there is usually no significant abdominal discomfort. If lower abdominal swelling occurs, pelvic inflammatory disease should be considered. If there is no pelvic inflammatory disease, but the lower abdomen is still swollen after intercourse, you should also consider whether the time of intercourse is close to the menstrual period. The pelvic cavity is congested during the premenstrual period, and this time intercourse will lead to increased pelvic congestion, so the feeling of lower abdominal swelling will be relatively more obvious. If the lower abdominal swelling lasts for a long time and is not very serious, no special treatment is needed; if the lower abdominal swelling lasts for a long time, even combined with pain or leucorrhea odor, fever, the situation is more serious, professional treatment is needed.