“… return to normal…” means to me someone is pooing soft and formed without any meds, like laxatives or stool softeners, or other aids such as suppositories or enemas, large or small.
For this to happen, there has to be enough poo in you large bowel to, at least, fill it partly full. If there's no poo in there, you won't go. And that's what a big enema does… it petty much completely empties you colon of all poo, from your rectum all the way to your cecum.
The time to ‘refill’ you colon with poo depends partly on what you eat. If you eat a low fiber diet it might take four days or more. (That's what the Apollo era astronauts did. No toilets in the spacecraft so they had to poo in plastic bags in zero g, hence tried not to). But if you eat a very high fiber diet, like a couple of bowls of All Bran, several times a day, you'll be full of poo and ready to go much more quickly.
For me, after having a closed system colonic, preceded by a 1500ml bag enema with a bit of soap (a pretty thorough cleanout), and eating normally after the session, I usually don't poo until the morning of the third or fourth day after the session.