I've suffered from IBS for at least 20 years, and it worsened when I got diagnosed with hypothyroidism. Frequently those who have hypothyroidism have IBS. I recently read on another forum that often times it's due to food allergies. I wished I would've found that about four years ago. That's when I started to discover my food allergies. I'd go several days without any IBS symptoms and was thankful. Then I'd eat an offending food and poof my symptoms had returned. Over time the return of symptoms got worse until I finally made the connection to a specific food I had eaten.
My symptoms include gas, diarrhea, nausea, and sometimes vomiting and stomach and intestinal pain followed by styes on my eyelids and acne on my head and face along with several areas of my skin breaking out in eczema.
Sometimes I'd only have gas and thought it was due to a supplement I had taken. At one point, severe gas was an ongoing symptom I lived with for about four months until I ate more than a small amount of the offending food and had the worst IBS symptoms ever in my life. I was close to going to the ED at my closest hospital. This time I had pain too. That's when I figured out the food which caused it.
Now that I've stopped eating most of the offending foods, my gas is completely gone and so are my IBS symptoms. My skin cleared up beautifully.
Well that is until I discovered another one allergy. UGH! The food is related to the other ones I'm allergic to so that would make sense. I'm on the tail end of that systemic reaction and feeling better each day.