I too, have had trouble with diarrhea since age 13. It started out only when I'd get nervous, but by age 22 I was having some type of diarrhea or constipation after almost every meal. My dad also has issues with diarrhea, and he told me to take Immodium. I never had any allergies before (I was tested at age 15), but when I was tested again at age 22, the scratch test revealed over 30 food and environmental allergies. My allergist (a prominant allergist at a university clinic in Chicago) had me do the traditional thing: cut out the reactive foods (gluten, dairy, etc.), and get on nasal spray and allergy medicine for the environmental ones.
For some people, it's as simple as that. Their IBS clears up when they cut out the food or foods that they're unknowingly reacting to. (See post in another thread by John14).
Gluten, dairy, and "spicy" foods are often common on the list for people with IBS. "Spicy" foods come from the nightshade family. Nightshades include all peppers (except black pepper), white potatoes, eggplant, and tomatoes. Nightshades produce solanine, which acts like a natural pesticide for the plant. In people, nightshades cause inflammation. When I eat nightshades, I get joint pain and burning eyes.
More people are developing corn and soy sensitivites, as well. Corn and soy are found in most processed foods under different names, making them hard to avoid. Corn is ascorbic acid and corn syrup/high fructose corn syrup. Soy is also lecithin and textured vegetable protein. Both corn and soy are often genetically modified nowadays, and no one has tested the effects of that on people. (See the documentary: The Future of Food).
There are also some food additives and chemical processes that we are exposed to, while previous generations were not. One of them is hydrogenated oils, or trans fats. These fats are chemically altered and very cheap and easy for the food industry to use. However, the body cannot process them very well, because they're not what nature intended. I always get diarrhea when I eat them. They are in almost all fast foods, even the ones that claim "Zero grams of trans fat per serving!" They're legally allowed like .5 grams "per serving," and if they shrink the serving size, they can use more trans fats. (See the documentary: InGREEDiants for the exact amount). Trans fats are also in all the major brands of breads, buns, crusts, rolls, etc. Companies are getting more creative with their labeling as consumers are learning more.
Other food additives that tend to be more involved with neurological issues include artificial sweeteners, artificial dyes, and flavor enhancers. The flavor enhancers go by 30 different names, the most common of which is MSG. If you keep craving the food, you'll keep buying it. I react to these in large enough quantities--I get headaches
and vision/balance issues.
Back to my history. After cutting out the recommended reactive foods, I felt better for a few months, but then all my symptoms returned. This time they had gotten even worse. I had horrible, foul, almost uncontrollable gas, and bad diarrhea. I brought a change of clothes to work, because if I didn't make it to the bathroom in time, I needed to change clothes. At that point, I began doing my own research. I knew there had to be more to it than that. I learned that I had Candida since age 13, and leaky gut since age 22. When I told my allergist, I was met with doubt. I learned later that Candida is a bit of a devisive issue in the medical community--some doctors think "only cancer patients can get it." The Candida was later confirmed by a blood test from a different doctor.
Candida is a fungus, and I have an overgrowth of it in my gut. I had a history of being on and off antibiotics frequently throughout childhood, and I'm certain that is the primary cause of my case. I also had mercury amalgam fillings, vaccines with mercury, and in high school, the same allergist gave my steroid inhalers and Prednisone for asthma. I just recently learned that my asthma was actually caused by Mycoplasma Pnemoniae, which no one tested for until now.
As a fungus, Candida thrives on heavy metals, steroids, sugars, and carbohydrates. Eliminating it requires dilligence, and diet alone will weaken it, but not kill it. Candida can also adapt itself to the antifungals that are being used to treat it if the antifungals are not rotated. (This aspect of rotation is often missed by people). I felt substantially better mood-wise after replacing my amalgam fillings with white ones and detoxing from the mercury, in particular. Mercury is often the cause of depression/anxiety issues. Pro-biotics are helpful in re-populating the gut with good bacteria after the Candida has been cleared out. While the Candida is still overgrown, there is no room on the gut walls for the pro-biotics to take hold. They'll only temporarily change the pH of the gut.
Leaky gut was the cause of my laundry list of allergies. With leaky gut, food is not digested correctly, causing malabsorption issues. The Candida takes some of the nutrients before the gut can absorb them. This leads to slight mal-nourishment. Secondly, large, under-digested food particles are absorbed by the gut. Those under-digested particles make their way into the blood stream, triggering an immune response by the body, which results in a food allergy or sensitivity. The body sees the food as an invader. I find that I have to eat fresher, nutrient-dense foods, or I am hungry because of this.
I'm currently working through these issues with the assistance of a nutritionist. I attended one of his talks at an Autism conference, and I was impressed with his approach Candida and leaky gut. I had others attempt to treat the Candida before, but they missed the rotation and a few other things.
I don't envy you entering college with IBS--it can be challenging to deal with socially. I'm sure many on this forum have experienced this at some point. In my case, the majority of my symptoms hit as I was finishing college, student-teaching, and working. As a teacher, it was mortifyingly embarrassing and quite humbling.
What are you planning on studying, anyway?
Best wishes on your health journey!