What Causes Frequent Bowel Movements, Stomach Pain And Nausea?

I had a colonoscopy 2 years ago (my 2nd one) and all was fine. In the past 2 months, I have had intermittent increased bowel movements, not really diarrhea but soft and foul smelling & increased gas. At times, I think symptoms are worsened by tomato-based foods and/or onions but in recent weeks, I have cut out onions and symptoms are fairly persistent. I wake up in the morning with pain in my stomach with periodic nausea but not vomiting. I have set an appt. with my PCP but cannot get in for another month. I also have a sore throat that comes and goes but it is not severe and may be unrelated. I have no other upper respiratory symptoms, am not diabetic, though my BS has creeped up a bit in past few years but I just had an A1C and was high normal. I am wondering if I should take something such as Immodium or just ride it out until I see my PCP in a month. I do have a family history (grandmother and several other extended family members who, as they got older, developed lactose intolerance and my son was very lactose intolerant as a baby (when switched from breast milk to reg. milk at about 15 months), but he outgrew it a few years later. What do you recommend?