Hi and thank you for your question. I am a verified Expert and I am happy to help you today. I would highly doubt Hep C as your antibodies were negative. It sounds more like anxiety to me, honestly. With Hep C your stool isn't yellow or light brown it's almost white.. an absolutely abnormal color that you would recognize as very unusual, right away. The lack of a gallbladder, when eating fatty foods can cause the diarrhea as well as the lighter color stool. As far as the pain.....
the lower right abdomen pain can be due to something called Irritable Bowel Syndrome....IBS is a term given to A FUNCTIONAL BOWEL DISORDER THAT CAUSES ALTERNATING DIARRHEA AND CONSTIPATION, (some people only have the diarrhea... while others have constipation)....ABDOMINAL PAIN AND BLOATING. a consistent bowel regimen will help you, if this is the case. .... my recommendation is for now, until this passes, eat bland food.. not raw vegetables.. but things like . chicken noodle soup.... saltine crackers and at least 8 glasses of water per day. Purchase Bio- K, which is an excellent probiotic that will not only help with regularity but also improve your immune system. Once this clears... purchase Benefiber..( Over the counter) and take it per package directions. This combined with Bio K will promote regular, productive, well formed, easy to pass stools.
Also...the liver is in the upper right quadrant... and the pain would be steady.
It sounds like you are over worrying, which is understandable... but I do hope this information gives you peace of mind:-)
Sharing of razors and toothbrushes
Remember Hep C is a blood to blood transmission. She would have to have bleeding gums and so would you.