<prompt> Which of the following does not occur in a patient with gastrinoma?Epigastric painDiarrhoeaBasal acid output BAO less than 15 mEq litreSerum gastrin levels 200 pgml  <response>: Ans. is c i.e., Basal acid output BAO less than 15mEqlitre BAO is usually more than 15 meqh in pts with gastrinoma 80 cases.A gastrinoma is a neuroendocrine tumour that secretes gastrin.The chronic hypergastrinemia leads to - gastric acid hypersecretion - peptic ulcer disease as well as diarrhoea.Symptoms of gastrinoma Zollinger-Ellison SyndromeAbdominal pain 70-100Diarrhoea 37-730 GERD 30-35Diagnosis of Gastrinoma or Zollinger Ellison Syndrome.The first step in evaluation of a patient suspected of having ZES or gastrinoma is to obtain a fasting gastrin level.Virtually all gastrinoma patients will have a gastrin level 150 to 200 pgml normal 150 pgmlThe next step in establishing a biochemical diagnosis of gastrinoma is to assess acid secretion. Up to 90 gastrinoma patients may have a BAO of 15 meqh normal 4 meqhA BAOMAO ratio .6 is highly suggestive of ZES, but a ratio of .6 does not exclude the diagnosis.Gastrin provocative tests are helpful in patients with indeterminant acid secretory studies. Three provocative tests are used.Secretin stimulation testCalcium infusion studyStandard meal testIn each of these tests gastrin level is measured after the stimulus i.e. secretin, gastrin, standard meal.Among these tests secretin test is the most specific and sensitive test, there is 200pg increase in serum gastrin level within 15 minutesAlso know this important point about the diagnosis of gastrinoma.If in a patient - the pH is 2.0 the gastrin level will determine further course gastrin level 1000 pgL - diagnosis of gastrinoma is established gastrin level 1000 pgL - determination of BAO and secretin provocative test is required. 