"The bottom line is there is not any beneficial effect and there is some risk associated with any enema and, in particular, using coffee," said Rajapaksa.
Enemas in general should only be used on the recommendation or guidance of a medical professional. Any liquid used as enema would have the same effect, she said, making the person defecate.
"Whenever you are inserting something into the rectum there is a danger of causing a tear in the lining," she said. "Over using enemas can sometimes lead to dehydration and it can basically lead to a decrease in bowel function."
When ingested, caffeine is a cathartic that causes the colon to contract and "move along," according to Rajapaksa. But when injected into the colon, caffeine can cause irritation.
"If it's a warm liquid you are using, then it can cause internal burns and some of the caffeine can be absorbed and those sensitive to caffeine, like pregnant women, have to be careful," she said.
As for Mike and Trina, they eventually seek help at the encouragement of her teenage son from a first marriage, Taylor.
"I don't want to get the phone call one day that you've keeled over from a heart attack," Taylor tells his mother in the TV series. "I want you to go see a doctor."
Mike admits he has cut back on the practice, telling ABCNews.com, "I don't do it daily anymore. It's a little time-consuming so I do like maintenance. I am not a medical professional, but I haven't had any complications or health problems."
And he is tolerant of his wife's addiction, he said, "because I love her."