IBS can be a nightmare but many doctors miss diagnose patients.
For anyone with a questionable digestive system (whether it's going to the potty too much, not regular, constant tummy issues, constant gas, etc.), examine your diet (write down what you eat). What RosenBud has mentioned above (even though it was dated many months ago), is excellent! Cutting out soda, junk food, dairy, wheat, etc, foods is the first step; i.e: Replace breads with gluten-free items (there are many gluten-free crackers, breads, cakes that taste soo good). Replace white rice with brown rice. Replace soda with water, but if that is way too extreme for you, do Crystal Light. Exercise is very important as well. You releave stress, loose wieght/tone your body and I've noticed that running helps with bowel issues.
Take a good brand of multi vitamins. You can get cheap ones like Centrum, but I would go with a higher brand. Also adding ProBiotic's is good. ProBiotic's come in many forms (yogurt, capsules, drinks, etc.)
If you need guidence, seek a naturopathic doc or even a wellness specialist. It may cost you an arm, but your being guided correctly.
Having a consistant colon cleanse; "ColonTonic" is what we call it here in Northern California. Whether you prefer to have the cleanse in a drink or tablet form. I recommend the "tube up the bum" method, lol. It's much more cleansing but it will take a few sessions. Also Detoxing, maybe not a colon cleanse & detox back to back. There are so many methods of detoxing. You can find many books & websites that have recipes available.
If all above doesn't help, seek a doc who can truely diagnose if you have IBS. But, please be advised that seeing your primary doc first would be the best. Asking questions whether it's okay for YOU to examine & detox yourself. Some people are at a higher risk of hurting themselves (due to whatever reason).
Overall, relax! I know life itself maybe stressful, but a person can only do/think about so much in a day. In the end after all the things are done above/tried, you will notice a difference within yourself. Better mind set, loose of wight, skin will look better, your menstral cycle will be better (i.e: a normal flow), breath will smell better (some people have bad breath coming from the stomach), etc.