It can be very serious and definitely you do need to be followed by a physician during this. Pancreatitis is not a good thing! Also, I had a patient once who told me that he had a stone blockage and pancreatitis and ended up with diabetes and on insulin from the damage done... that is an extreme case and shows the importance of a medical follow up to make sure the alternative methods are working for you!
On a personal note, I have used lemon juice with olive oil in the past and "cured" my problems with the severe gall bladder attacks and avoided surgery. I also take dandelion if I feel any possible "twinges" just to make sure it doesn't go into a full fledged attack. Eating a low fat diet and avoiding spicy foods can help also.