I had anal sex for the first time over the last two days well last night a few hours after i started having sharp stomach pains that wrapped around to my back no fever bo blood in stools then this morning i had loose stools. still got stomach pains?

Although the: chances are slim that your symptoms are connected to the anal sexual contact (probably a more common stomach upset (viral or dietary origin) there are sexually transmitted diseases which can be transmitted anally..gonorrhea and non-specific urethrits are examples. If your partner wore a condom as he should have for his own protection, this would diminish that possibility. See your GYN !!