This are actually three similar conditions...I've ordered them from the less severe to the most severe.
IBS - Irritable Bowel Syndrome
IBD - Inflamatory Bowel Disease. This is also known as ulcerative colitis.
Chron's - Can affect any part of the GI tract, from the mouth to the colon.
It's important to get treatment if you ever suspect something's not right. Get diagnosed. At least if you get diagnosed, you can get treatment that will make things a little better. Stay away from alcohol, milk, and greasy foods... You may also have a reaction to some fresh fruits/vegetables.
There are 2 major treatments for Chron's and IBD. For IBS, there are some milder treatments, but depending on what your doctor suggests you may need something stronger.
ASACOL, a delayed release aspirin helps calm the muscles of the colon. Major side effects of this are ringing of the ears and just the realization that you have to take a handful of pills every day.
The other major treatment are steroidal meds. They help the area heal and shouldn't be taken long term. However, some cases are so severe that this is the only thing that gives the patients relief. They have to take a small dose every day. Side effects of this include upset stomach, increased appetite, acne, mood swings, etc...