My dr prescribed multi-vitamin supplement (capsules). but even taking it after a meal. i get severe abdominal cramps that last about 30 mins?

Stop it; change it: This happens to a minority of people who take multiple vitamins. Often it is the iron in the vitamin that causes the gastrointestinal distress. First, I would stop the multiple vitamin to prove that it is responsible for your discomfort. Then, switch to another brand, especially looking at the iron. Iron gluconate is often better tolerated.Your doctor/pharmacist can suggest alternatives. Good luck