Loose Stool, Gas

For the past two years I have been having digestive issues. I have much more gas (flatulence) than normal - to the point where it seems like I am passing gas all the time. My stool used to be a single solid mass and now it’s almost always loose and very soft even diarrhea at times. The stool tends to be "greasy" (sticks to the toilet bowl) and smells more than normal. Sometimes it is "pencil thin" but not always. The closest analogy I can come up with is that it’s the consistency of soft serve ice cream. I do not have constipation or pain. I've noticed no pus or blood and the stool color is normal.

I've been into see my primary care physician who sent me to have a colonoscopy - that turned out normal - no polyps or anything unusual. He also sent several stool samples into be analyzed and those returned as normal.

My doctor seems at a loss for what else to suggest but has me now trying a lactose free diet. I've been on that for about 5 days with no improvement. I am going to continue the lactose free diet for another week and a half or so but I'm skeptical its helping.

He also wanted me to try a diet which reduced my intake of soluble or insoluble fiber - I can't recall which. I begin that after the lactose free diet. He recommended that I eat oatmeal and stay away from foods that can cause gas like broccoli, beans, cucumbers etc.

Some possibly related items:
This started around the time that I had co2 laser wart removal for warts inside my rectum. I had to repeat the procedure a year later due to re-occurrence. Since the second treatment (a year ago) I've had no re-occurrence of warts (I've had regular checkups at the std clinic). I initially dismissed the loose stools as just a normal part of the healing process from the wart removal but my doctor has told me that it’s been sufficient time that I should be entirely healed.

Around the same time I  reduced my intact of meat substantially (as my partner is vegetarian) but I do still eat meat about once a week.

Finally I had a re-occurring sinus infection which I took several different types of strong antibiotics. It turns out the infection was caused by a poorly performed root canal and I had developed a dental abscess.

The one last thing I can think to mention is that my doctor noted I gained 15 pounds in this time frame. Weather that’s related to this issue or wishful thinking I'm not sure. I would think that a vegetarian diet would be lower calorie and thus I would lose not gain weight. I haven't changed my level of activity significantly.

I've been searching online for conditions that match my symptoms and can't find anything that matches well. I'm hopeful that someone here may have some suggestions for what might fit.

I'll be going back to my doctors in a few weeks if neither of the diet changes (no cheese, reduce fiber) helps. My doctor seemed to suggest that he was out of ideas and as long as it was just gas and loose stool that I might have to live with it. I'm not content with that answer as I know this is not "normal" but short of insisting on a referral to a specialist (what type of doctor would I need to see?) I'm not sure what else to insist upon.

Thanks In Advance for any help.