Robert S. Mueller III is giving me a case of heartburn.

The length of this probe is giving me the willies about its future.

Mueller’s probe into The Russia Thing needs to conclude. I hope it happens soon. My fear is that the longer it goes the greater the chance that Donald J. Trump will do something so profoundly stupid that he will hurl the nation into the mother of constitutional crises.

What would the president do? He might order the Department of Justice to fire Mueller. Sure, he keeps pledging — sort of — to let Mueller finish his job. However, I trust the president only as far as I can throw a 239-pound individual.

My heartburn worsens when I consider that I also want Mueller to be as thorough as humanly possible before he wraps it up. He has obtained 37 indictments and guilty pleas already. Some of those indictments include the president’s closest campaign aides and key White House staffers. The latest indictment of Trump confidant Roger Stone is providing an sideshow that would make P.T. Barnum proud.

Yes, I want Mueller to pick through the evidence he has collected already into alleged “collusion” with Russians who attacked our electoral system. I want him to pore over every single bit of it.

Time, though, is not Mueller’s ally. A new attorney general, William Barr, is likely to be approved by the U.S. Senate. I hope that confirmation comes soon so that Barr — a former AG during the Bush 41 administration — can take command; he then can push the Trump sycophant, acting AG Matthew Whitaker, out of the way.

But on another level, I want this probe to end so we can move on to the next thing, which is to digest its findings, or at least those findings that Mueller deigns to release to the public. My strongest hope is that Mueller releases virtually all of it, keeping only that information that contains national security information away from public view.

I want it concluded. But not in a hurry-up fashion. I also want the president to keep his hands off of Mueller’s work and I also want Mueller to finish every little detail of this exhaustive work.

Pass the Pepto . . .