Immediate solution: Loperamide (freezes digestive muscles)
Long term solution: Therapy for Social Anxiety
This issue is simply an outlet for your Social Anxiety - I will explain below. But in the meantime, take Loperamide for an immediate solution.
The same issue has plagued me for the last ten years since I was 14. It first happened in an exam, but it was nothing to do with hunger - more my lower intestinal tract pushing gas around. The thing is, no one even seemed to notice or laugh, but I was still overcome with this crippling feeling of embarrassment and the feeling that I just wanted the ground to swallow me up. It was honestly the worst feeling I had ever experienced. The worst part was, no one understood what I was going through. When my headteacher left in secondary school, we had an impromptu assembly with the entire school of 1000 students and I was the only one sat outside the assembly hall.
What I have discovered after 10 years is this that this issue stems entirely from Social Phobia. Sure, you can tailor your diet to eliminate gas, but as long as you're still socially anxious, the noises will continue. It is simply an outlet for your Social Anxiety. I know this because when I started University, my entire course was sat together in a silent room for the introductory speech. No one was even talking at first because they didn't know each other, so no background noise. Classic anxiety-provoking situation. I sat, waiting for my guts to start churning and cause embarrassment. However, they didn't; I was constipated so the air that would usually move around my guts and cause noise, stayed in place. This was so bizarre for me because I didn't have an outlet for my anxiety. Then, the teacher made us walk around the classroom and introduce ourselves to random people. As I was speaking to this person, my face all of a sudden flushed with heat and I went bright red. Uncontrollable red. I had no idea why and I had never experienced anything like this before. In the middle of this person's sentence, I rushed out of the room and didn't come back, without saying a word. This person was probably left totally bafled and thought I was a complete weirdo.
From then on, I developed Face-Turning-Red-When-Speaking-To-Anyone Phobia. I couldn't order a coffee without turning bright red, I couldn't answer the front door to the Postman without the fear of turning red and at my lowest point, I couldn't even have a conversation with my own Mother without turning red! But the funny thing is, since developing this new Social Phobia, the 'uncontrollable' fear of my stomach making a noise in a quiet room totally disappeared! I was no longer afraid of sitting in a quiet room or highly controlling my diet to eliminate gas. All of my Social Anxieties were now preoccupied with the fear of my face turning red. I couldn't even understand why I used to be so nervous about quiet rooms before now.
Then, after three years of suffering from Red Face, one day, I was having dinner at a family friends house that I had never been to before. We were all sat around the dinner table and it was dead silent. I felt a gurgling sensation in my lower gut that would intermittently get louder and louder. I got the urge to pass gas, but the bathroom was right next to the dining room and I didn't want anyone to hear. I got myself so worked up about my gas gurgling - that everyone could obviously hear but were too polite to comment on - and from then on, like at the flick of a switch, my Red Face Social Anxiety had completely disappeared and was replaced again with my stomach noises in quiet room anxiety. I wonder what it will be next?