Dealing with gi issues + weight loss and very worried

Hi, so im a 18 year old male have been pretty stressed and worried ever since a week and a half ago where I started having these gi issues like my gut was irritated like something felt off. I always dealt with gi issues and I have been taking gut health seriously over the past 2 years so this really scares me because i started to have diarrhea and stomach felt upset + abdominal pain on the right side and left mainly (left) side and that gotten better but then.. weight loss I was 160Ibs before this all really started and now after a week and like 3 days I’m 154.6 I’m scared that something serious is going on with my body that needs attention I went to a gi doctor that my primary gi recommended and I was told that it could be Ibs or like a viral infection I asked for a colonoscopy and she said that that’s not really necessary and that it would not “really show
anything “ but she granted my request to do the colonoscopy to give me a peace of mind. Also she said that she didn’t 100% disagree with the colonoscopy because of the weight dropping I mentioned. So I’m really scared at this point I try to workout eat clean + healthy and take care of my body and health, and I have been trying to bulk up
To about 165Ibs to 170Ibs which I hit 165 before but dropped since I think it was water weight.. please if anyone read this any tips or suggestions?