It does not sound like you are a complainer; you would just like to understand what is going on with your body. Part of the problem is that there seems to be two separate medical issues here.
Geographic tongue is a benign inflammation ( benign means it will not turn into anything serious). What happens is irregular patches of smooth tongue are intermixed with rougher areas which results in the tongue looking like a map. The cause of geographic tongue is unknown although some doctors suspect allergies are involved. Other causes include local irritation of a small portion of the tongue from hot spicy foods, alcohol, tobacco or some other irritant. If you have geographic tongue you should avoid these items. There are no tests involved in diagnosing geographic tongue; examination of the tongue by a medical professional is usually sufficient.
Geographic tongue is not associated with any of the symptoms that you mentioned. Check back with your doctor again and try to focus on the symptoms that are bothering you that are not related to your tongue. Try to find one doctor that you are comfortable working with and stick with him/her until you feel you have some answers to why you are experiencing these problems. If you keep switching doctors it is hard to get consistency, which is very important in proper medical care.
It is also possible that your condition has been misdiagnosed. Oral and/or tongue lesions, abdominal pain and diarrhea can also be features of Inflammatory Bowel Disease. If you feel as if you are not satisfied with your doctor's approach or answers, you should consider consulting a specialist called a gastroenterologist.
If you live in northern New Jersey and would like to meet with a doctor from the Adolescent/Young Adult Center For Health, you can call 973.971.6475 for an appointment.