Can a severe form of bacterial vaginosis cause stomach bloating and pain?

Yes, not regularly: GI symptoms such as nausea, vomiting, upper abdominal dyscomfor and abdominal bloating including diarrhea or constipation are usually common in any form of pelvic infection such as STD, UTI, pyelonephritis and enddometriosis. However, these are not the primary or most common symptoms. After treatment if GI symptoms persist consider alternative diagnosis like GERD, PUD & hepatobiliary abnormalities

Yes, PID!: On occasion it is possible to develop pelvic inflammatory disease from overgrowth of Garderella vaginalis which is the bacterium that causes BV. Talk to your doctor and get seen right away, as PID can result in scarring and infertility. Call your GYN and if you can't be seen today consider a visit to urgent care. Take care and feel beter!