I woke up the other day with massive stomach cramping and fever. I'm still feeling a wee off. Either I really need to "pass some gas" or I have one or many of the following issues: gastroenteritis, appendicitis, gastritis, esophagitis, diverticulitis, Crohn's disease, ulcerative colitis, microscopic colitis, hernia, intussusception, volvulus, post-surgical adhesions, tumours, superior mesenteric artery syndrome, severe constipation, hemorrhoids, embolism, thrombosis, hemorrhage, sickle cell disease, abdominal angina, blood vessel compression (such as celiac artery compression syndrome),Postural orthostatic tachycardia syndrome, peptic ulcer, lactose intolerance, coeliac disease, food allergies