Genetic Testing for Hereditary Pancreatitis

hi... i am 48 years old and was diagnosed with pancreatitis a year ago, after having to go to the ER twice during painful attacks. i have often had similar, but milder, pain, nausea and vomiting throughout my late teens and adult life (ever since having severe dysentery during a trip to mexico when i was 14). i always assumed i just had a delicate stomach and high susceptibility to food poisoning, possibly because of the dysentery.

this time, though, when it was so bad i had to go to the ER, then was hospitalized the 2nd time for 4 days, the docs and gastroenterologist gave me a CT Scan, Ultrasound, and MRI (or, a different name... like, MRCP?) and blood tests, so diagnosed pancreatitis, but found no specific cause of it - i rarely drink alcohol, and i had no signs of gallstones. they also have no idea if it is chronic or acute.

i vaguely recall my grandma had frequent bouts of extreme stomach pain but don't know if she was diagnosed with pancreatitis - most people in our family considered her a hypochondriac and dismissed all her complaints.

now, my 12 year old son was diagnosed with pancreatitis a few days ago after suffering for several days. we took him to the ER twice, two days in a row. he also has always seemed to have a delicate stomach with frequent, yet mild, bouts of vomiting. by mild, i mean that he would throw up once in the morning, be allowed to stay home from school, and then feel fine the rest of the day. leading us to suspect that he was just trying to get out of going to school. on the other hand, when he was about 4 or 5, he would sometimes have so much pain after dinner that we took him to his pediatrician, who ran some tests on a stool sample, looking for parasites, and said she couldn't find anything, but that if it continued, she refer him to a specialist in a city 2 hours away. it didn't continue, so we didn't pursue it further.

he has continued to have pain since coming home from the hospital 2 days ago, which we are managing with painkillers and diet. we are waiting for his new pediatrician (we just moved) to call back to give us an appt.

my question is, at what point do we ask for that gene test i've read about? is it widely available? expensive? useful?

should i demand that his new pediatrician (who has never seen him) order the gene test? or be more patient to see if this thing even continues? the docs at the hospital said it's most likely due to a viral infection, but could also be hereditary based on my own history.