Introduction and Overview
This is Part 3 of a five-part series relating to pediatric feeding. Part 1 covered typical development of feeding to provide an idea of what feeding is supposed to look like in the typically developing feeder. Part 2 focused on prematurity and the co-occurring diagnoses and long-term outcomes associated with that; again, that course was tied back to feeding development and feeding problems. This course is going to discuss constipation. It will become infinitely clear very quickly that constipation is not only a problem that can influence feeding, but conversely, it is also a problem that is influenced by feeding disorders.
Some of the content in the handouts may not be reviewed specifically, but my intention was to provide as much information as possible so that you can build a toolbox of information around this topic and be prepared to use it to help your clients and families.
My disclosures are that I am an Associate Professor and Director of Clinical Education at the University of Louisville. I do receive a salary for those responsibilities and I also received a stipend from SpeechPathology.com to teach this course.
First, we need to understand what defecation is. Defecation is the process that occurs to rid the body of what is left after the digestive system has absorbed the nutrients and the fluids. Essentially, this act allows the child to remove all the waste that is left over, and it also allows the child to make room for more. That is a very critical point as we go through this course.
Let’s do a quick review of the anatomy. The partially digested material that comes from the small intestine will go into the cecum, which is right at the beginning of the ascending colon. This partially digested material - called chyme - gets in there, mixes with the good bacteria, and creates a nice fecal matter that is then sent up into the ascending colon. The ascending colon absorbs anything that is good - the water, the nutrients, and so on - and starts pulling those nutrients out to use and puts it into the bloodstream. Then, the fecal matter is transferred into the transverse colon, where most of that absorption happens, because it is the longest part of the large intestine. It goes through the transverse colon, and down the descending colon. Once it gets into the descending colon, some of it will stay there for storage and some will also go into the sigmoid colon. The sigmoid colon has a couple of main functions: one being the storage of feces, and another is the action of pushing the feces into the rectum during defecation. Once that feces is in the rectum, it is going to put pressure on the rectal walls, and that signals stretch receptors and sends nerve impulses to the brain. That person will feel discomfort and pressure occurring in the rectum, and the internal anal sphincter will relax. The only thing left to happen is that the external sphincter has to relax, but that is under voluntary muscle control, so the child has to be ready to release that. That is where we get some of the constipation that we will discuss as we proceed.
Again, there is mass movement, then you have the defecation reflex where the stretch receptors signal the rectum that there is something in there, and the child can either keep the external anal sphincter contracted, which will delay defecation, or he/she can relax that external sphincter and defecation can occur. That is basically what happens in the typical world of defecation.
Nervous System Control of Defecation
The gastrointestinal (GI) tract is controlled by the autonomic nervous system. Sympathetic and parasympathetic nerves work together, and defecation has voluntary and involuntarily controlled functions.
What is constipation? It is defecation that is unsatisfactory because of infrequent stools, difficult passage, or seemingly incomplete defecation. The reason that that is such a big deal in the world of feeding is because we are therapists who are working with children with feeding disorders, and constipation can have an impact on that child's willingness to take in more food. The more rigid the child is about taking in food - and a variety of food - the more likely he is to have this vicious cycle of having more constipation. So as you can see, it has an important relationship with feeding.
Facts and Statistics
In terms of facts and statistics, constipation is a symptom; it is not its own disease. There are more than four million people in the US that complain about frequent constipation. In a year, two and a half million of those people will visit a physician to get help with constipation. Twelve percent of people worldwide will suffer from constipation. Note the last bullet point: childhood constipation worldwide ranges from .7% to 29.6%. That is a really broad number.
Categories of Constipation
As we are trying to understand constipation, let's look at it from a classification standpoint. There is organic constipation or functional constipation. Organic constipation is caused by an underlying pathology. It occurs in 5-10% of cases, and it is more likely to present in the first month of life. Functional constipation is when there is no identifiable pathological condition. It is the most common cause in children, and usually it is because a child is withholding his or her feces purposely to avoid painful bowel movements. We see this type much more than the organic type.
Let’s review some of the organic etiologies for a child under one year of age who has that sort of constipation. We will talk about Hirschsprung disease and anorectal malformations as we proceed. Other causes are central and spinal neurologic abnormalities, cystic fibrosis, and metabolic abnormalities.
For children over one year of age, etiologies include nerve, muscle, and metabolic disorders. Medications, which I will address later, may also be implicated in terms of causing constipation. There are also connective tissue disorders that can cause constipation; such as Marfan syndrome, if you are familiar with that.
Functional Constipation Diagnosis
When considering contributing factors, we are not talking anatomy or physiology. We are talking about behavior, environment, development, psychiatric issues, and cognition. Maybe the child gets a really low-fiber diet or a diet with minimal variety, and/or she may have reduced fluid intake. All of these things can impact a child's ability to defecate and can result in functional constipation.
How do the doctors know how to diagnose this? Fortunately, there are several classification systems, including:
- Rome-IV (recommended by NASPGHAN & ESPGHAN)
- National Institute for Health and Care Excellence
- Paris Consensus on Childhood Constipation
- Iowa Criteria
- Gfroerer and Rolle
Rome-IV. The Rome-IV is the one that we will reference in this course because it is the one recommended by both the North American Society for Pediatric Gastroenterology (NASPGHAN) and the European Society (ESPGHAN. To provide a brief history, the Rome has been around since 1994, but when it first began, it was only criteria for adults. Then in 1999, they developed some standardized criteria for children. In 2006, they decided to make the distinction between young children and older children. In 2016, the Rome-IV was developed because there had been so much pediatric GI research over that span of 10 years.
Changes to criteria in Rome-IV. The specific changes in this new version include, for the infant-toddler category, new criteria for infant dyschezia. This is a condition where a healthy infant is struggling to stool for more than 10 minutes or so. The criteria used to say that the child had to be straining and crying, and the diagnosis could be given up until the age of six months. Now the criteria say that the child simply has to have difficulty stooling over more than 10 minutes at a time, and this diagnosis can be given up to nine months of age. Another change is that they now differentiate between children who have been toilet trained and those who have not, and then they also address issues about pain in the new criteria.
In the childhood/adolescent age range, the criteria haven’t changed for functional constipation. But, the time period for diagnosis has changed from two months to one month which gets the child help more quickly.
Current diagnostic criteria. To diagnose functional constipation in infants and children less than four years of age, they have to present with at least two of the following symptoms for one month, rather than the two months that it used to be:
- 2 or less defecations per week
- History of (H/O) excessive stool retention
- H/O painful/hard bowel movements
- H/O large diameter stools
- Presence of large fecal mass in rectum
For older children age four and above, all of those same criteria apply, plus they can also include at least one episode of fecal incontinence, where some of the feces will leak into the underwear. Another criterion that has been added is a history of retentive posturing or excessive volitional stool retention. This might include actions such as crossing the legs so as not to stool, holding on to a table so as not to stool, or other similar behaviors.
SLPs are not going to do this comprehensive examination – much of it is specifically done by the physician. But it is critical for us to know what is included in a really thorough constipation evaluation. That way, when our families come in and report, “They just did this or they just did that,” then we are aware and realize that maybe there is something missing. We can then advocate for the family and ask the physician to do more. Components of the examination may include:
- Physical exam
- Blood tests
- Abdominal x-ray
- Barium enema
- Sigmoidoscopy or colonoscopy
- Colorectal transit study
- Anorectal manometry
- Colonic motility studies
We are going to talk about each of these examination components.
We are going to be asking some of these things anyway as part of our own evaluation. We want a detailed history of medical diagnoses; that is, everything that the child has ever been diagnosed with. We want a detailed history of newborn stooling because that is one of the best ways to determine if somebody has an organic or a functional problem. We know, for example, that one of the telltale signs of Hirschsprung - which is usually diagnosed under a year of age - is that the infant will not stool in the first 48 hours of life. Therefore, if a parent of an infant says to you, “He did not stool for the first 48 hours” and there is also this symptom and that symptom, you know at that point you really need to get GI involved.
You are also going to ask the family, as part of your feeding evaluation, for a detailed history of current stooling patterns. If the child is stooling every four days and is struggling, that may be impacting feeding. You can also ask the parent to keep a diary of the child's stooling. If you do suspect that there is a problem, then you want to ask, “How long has the child been doing this? When did it all begin? Does the child feel pain? Does she have blood in her stool?” Again, you are going to report this to the physician.
If there is a history of abdominal pain, we certainly want to know that. A history of urinary tract infections is important, because many of the muscles and nerves that control bladder function also control bowel function. If the child has a full colon, it can push on the bladder and cause daytime wetting or nighttime wetting that is atypical for that child.
We need to ask about any history of psychological concerns. For example, does the child have a lot of anxiety around stooling, or related to feeding? Put all of those pieces together. Again, ask the parent to keep a dietary log for three days and show it to you so that you can see how much fiber the child is getting, how much dairy the child is getting, and so on. That will tell you a lot about feeding, but it may also give some clues into what is going on with stooling.
Lastly, you want to obtain a description of stool size and consistency. Sometimes when I have asked families to describe this, it is very difficult for them. If you have a tool such as the Bristol Stool Chart, that can be very helpful. Each type of stool has implications that you should think about and that you will want to report to the doctor.
Type 1 consists of hard, little lumps. They are hard on the child to pass; the child can get them out but it is not pleasant. This type is often indicative of not enough bacteria, which means that the water the child is ingesting is not really bonding to anything.
Type 2 is often associated with organic problems as well. It is the most painful of all because the maximum size of that stool is sometimes larger than the actual anal opening, and you may see a lot of straining and a child who does not want to defecate because of this. They may not defecate very often because it takes so long to get that out.
Type 3 is not much better than Type 2. It is essentially the same except the child may be fortunate enough to defecate once a week and get that out. But again, the diameter is painful for them.
Type 4 and Type 5 are the best, with Type 5 being the ideal. Type 4 is when somebody goes once per day. Type 5 tends to be the child who will defecate after large meals, and that is what we really want to see.
Type 6 tends to be a loose stool. The child may be on laxatives and that is what creates that. They may have a little faster motility, and maybe a little messier cleanup; but ultimately, we would still rather have Type 6 than Types 1, 2 or 3.
Type 7 can be a little deceiving. It looks like diarrhea, and is usually watery, with no solid pieces. That is not always the case, though. Sometimes kids can have an impaction in their bowel; that is, large pieces of stool that are stuck in that bowel and the only thing that can get past to get out is this watery little trickle of feces. When you see that, if there is not a lot of it coming out, it is a red flag that maybe it is trying to work its way around some impaction. Again, who wants to eat when they are feeling like that?
Again, we will do some of these components, but certainly not all. We are certainly going to take a look at the child's general appearance when she comes into our office. Is she lethargic? Is she energetic? What does her color look like? Does she have a rather grayish color, or is she a little bit yellow? We just want to make note of all these things.
You may or may not do vital signs in your clinic; some people do, some people do not. You want to look at his growth, and how much he weighs. Are there any concerns from the pediatrician (or whoever referred to you) about height and growth?