Internists rhymes with:
abortionists, agonists, balloonists, botanists, cartoonists, colonists, communists', constitutionists, extortionists, hygienists, impressionists, interventionists, isolationists, machinists, machinists', misogynists, noncommunists, nutritionists, opportunists, peronists, preservationists, protectionists, receptionists, rejectionists, reservationists, revisionists, revolutionists, secessionists, segregationists, shamanists, stalinists, unionists, zionists