Abdominal pain , vomiting, lower back pain , dry mouth, chest pain that comes and goes. ultrasound normal except mesentric reactive lymph nodes. blood count normal. what can the problem be ? does this justify a visit to the er? going for +- a month

See below: You have obviously been examined and investigated by a doctor. It is unfortunate that it did not resolve the matter, you may go to the ER if you have more pain, however, ER will only address the acute issue and not necessarily the underlying cause. You need to contact your primary care provider for continuing care. Wish you good health!

Abdominal symptoms: If your symptoms persist I would want consultations with both a gastroenterologist and an abdominal surgeon to touch all the bases. Inflammatory bowel disease like Crohn's,atypical appendicitis or recurrent incomplete intestinal obstruction are considerations here. The chest discomfort appears nonspecific. I feel more testing is warranted in view of ongoing symptoms.