Since you have found IBS symptoms familiar to you during these period of 2 years, along with stomach noises, it is very possible that you have this condition.
IBS symptoms are more prominent during morning hours and when the one isn't relaxing (classes, there is always a dose of stress).
IBS is a diagnosis of exclusion, or in other words, when you doctor doesn't find anything positive on gastrointestinal examinations and she/he thinks you have IBS symptoms, that you'll be diagnosed as IBS sufferer.
Talk with your physician (drug therapy for IBS, consisting of antispasmodics and antidepressants, usually relieves intensive muscle contractions of gut in IBS sufferer)!