Hello. Thank you for writing to us at healthcaremagic Unprotected Oral sex with a commercial sex worker (csw) is a risk factor for STD s. I don t think your gastrointestinal symptoms are related to oral sex. Oral sex can transmit gonorrhea, chlamydia, syphilis and herpes and even HIV. Oral sex is generally considered to be safe in terms of HIV but this not the case always. HIV is a risk if either of the sexual partners engaged in oral sex has active sores, which increases the risk. It is important to screen for STD s at appropriate time after unprotected sex because STD s may be clinically silent and may not manifest for weeks or months after an infection is acquired. Since its already been 3 months since this episode therefore I suggest you to undergo a screening test for STD s. Testing for gonorrhea or chlamydia is easy. A swab test for detecting microbial DNA can be done earliest at 2 weeks post sexual contact. Herpes can be detected earliest at 2 weeks with a blood test for Hsv type 1 &2 by ELISA. Screening for HIV and syphilis can be done earliest at 1 month and to be repeated later at 3 months for a conclusive result. Regards Always practice safe sex! with a single or trustworthy sexual partner.