Is there a way to get gentle, quick relief of constipation?

Fiber. Start with fiber and water. Then add each one if the first doesn't work 1. Fiber 2. Magnesium 3. Mineral oil 4. Miralax see your doctor if things don't improve.
Yes. The current mainstay of acute treatment of constipation can involve stool softeners and/or polyethylene glycol, both of which are over the counter.