The Modified O’Reagan Protocol for Pediatric Voiding Problems.

I recently became aware of the existence of the Modified O’Reagan Protocol (MOP) via a parent email that included an attachment titled “The Physician’s guide to MOP”.

MOP is based on the premise that constipation Is the cause of all voiding problems in the pediatric population, including nocturnal enuresis, daytime accidents, encopresis (stool accidents) and recurrent UTI’s –excluding anatomic causes of voiding issues like myelomeningocele, bladder exstrophy, posterior urethral valves, etc.

This is the x-ray of a 4-year-old girl with recurrent UTI’s and daytime accidents with severe constipation:

severe constipation in a child KUB

The regimen consists of “cleaning the rectum” with daily enemas for several weeks to months to allow it to shrink back to normal size.

Dr. Steve Hodges, from Wake Forest University School of Medicine, modified the O’Reagan protocol and called it MOP. He claims to have used MOP for a decade with amazing results and has a website where he sells MOP books, pamphlets, videos, and online consultations.

What does MOP consist of?

  1. Daily enemas for 30 days, followed by:
  2. Every other day enemas for 30 days, followed by:
  3. Twice a week enemas for 30 days
  4. Daily Oral laxatives for 6 months.

Enema options

  • Phosphate enema (pediatric or adult size)
  • Liquid glycerin suppository (pediatric or adult size)

Oral laxative options

  • Miralax
  • Magnesium citrate
  • Lactulose
  • Magnesium hydroxide

MOP should be first approved by a physician as some children with chronic renal disease can be hurt by phosphate enemas.


“But my child poops every day and he still has bedwetting, daytime accidents, recurrent UTI’s, and/or encopresis. He is not constipated!”

Nowadays constipation is diagnosed by history and exam — and not by rectal exam or x-rays. Families don’t consider their children constipated if they seem to have regular bowel movements that are not painful.

MOP is based on the premise that a full rectum that does not empty completely is the cause of urinary problems. This type of “occult constipation” cannot be diagnosed without x-rays or a rectal exam.

Only an x-ray can demonstrate to the families the stool in the rectum causing the urinary problems. Any amount of stool in the rectum is abnormal: the function of the rectum is not to store stool but to sense it and immediately empty it.

Most GI doctors are not familiar with this type of “occult constipation” due to the fact that the main symptoms are urinary and not GI related.


The problem with oral laxatives

Most pediatric urologists recognize constipation as the main cause of urinary problems. Since I started my practice,  I have treated constipation with a bowel cleanout (a full bottle of Miralax mixed with 1 quart of Gatorade) followed by combinations of daily Miralax and Ex-Lax. In addition, I have recommended sit times after meals — 5-10 minutes on the potty — and drinking water every 2-3 hours during the day.

However, oral laxatives can be problematic:

  1. Some children don’t like to take them; they may take a sip or two of the glass of water that contains the Miralax, but hardly ever finish the whole thing.
  2. Oral medicines can cause the stool to be too liquidy resulting in stool accidents. Soiled clothes/underwear discourages the child and family from continuing treatment. Also, parents see accidents as proof that their child is not constipated.


Why enemas might be a better option

Enemas simplify the treatment of constipation by giving the family and child control over the timing of the bowel movement. That means no accidents at school, while watching T.V, or when out and about; no fighting with a child that does not want to drink his Miralax, sit on the toilet, or drink water.


MOP plus

For children not responding to regular MOP, Dr. Hodges recommends MOP plus:

High volume saline enemas:

  • Ages 4 to 7: 300 ml saline
  • Ages 8+: 600 ml saline
  • Supplemented with 10-30 ml of glycerin or liquid castile soap


Is there any scientific evidence supporting MOP?


This is the tricky part. Conceptually, I was sold on MOP as soon as I read the Physician’s Guide to MOP. For several years, I have been dissatisfied with my management of constipation mostly due to the difficulties titrating the amounts of oral laxatives on a daily basis and the inconveniences of bowel clean-outs. I can clearly understand how the rectum can remain full with hard stool despite industrial amounts of oral laxatives. MOP makes sense to me. That been said, the evidence supporting its use is poor at best.

There are basically 2 papers supporting MOP:

There are no studies of MOP in patients with primary monosymptomatic nocturnal enuresis.

Bottom line, there is little scientific evidence to support the use of MOP.



Constipation is the main cause of encopresis and likely a major contributor to recurrent UTI’s and daytime urinary accidents. On the other hand, the role of constipation in primary monosymptomatic nocturnal enuresis is probably minor.

Conceptually, daily enemas appear superior to oral laxatives at tackling a dilated rectum that does not empty completely.

MOP is a cheap, safe, and easy way to deal with “occult constipation” causing urinary problems.

Because the potential for harm is low, I have no problem recommending MOP despite the lack of high-quality evidence supporting its use.

Leave a Comment