FRI is a symptom rather than a disease. Through outpatient EMRS screening, many pediatricians lack awareness or ambiguous probability of this symptom, and thus diagnose other FGIDs such as constipation, difficulty defecation, or Functional fecal retention. FC is mainly manifested by a decrease in the number of stools accompanied by dryness of stool characteristics. The etiology is often caused by factors such as unreasonable diet structure and long-term restraint of defecation. Defecation difficulties in infants are accompanied by screaming and crying during defecation, flushing is often caused by laborious defecation. The defecation time and labor symptoms can last for tens of minutes, and defecation can occur several times a day. Functional fecal retention occurs at older age and is more common in infants and young children after foods supplementation. It is a pre-symptom of FC and may eventually develop into FC. Although there is no precise definition of FRI, it can be clearly distinguished from the above diseases by its clinical symptoms.
In this study, the infants with fecal retention started from more than 20 days to 6 months of age, with an average age of 3.6 ± 1.5 months. Children with FC are generally older and often associated with dietary supplements. The duration of FRI ranged from 1 month to 5 months, with an average of 2.6 ± 1.1 months. The symptoms of FC may last for months or even years, and are prone to recurrent episodes. 63.3% of the feeding methods are mainly pure breast milk, which may be related to public health's active promotion of breastfeeding and higher breast milk penetration rate, while children with FC are mainly fed with formula milk. The above clinical characteristics suggest that FRI and FC may be two different mechanisms. Since most babies with fecal retention are breastfeeding, some guardians may consider there is something wrong with the milk and stop breastfeeding. Medical staff should always emphasize the benefits of breastfeeding and provide appropriate support to ensure that the guardian continues breastfeeding.
The cause of FRI is not known. As some babies will have a combination of laborious defecation, and the onset age of symptoms is also similar to the babies with difficulty defecation, all begin to show symptoms several weeks after birth. Therefore, some of the causes of difficulty defecation of infants such as intra-abdominal pressure inconsistencies in elevation and relaxation of pelvic floor muscles may also cause FRI. In addition, abnormal colorectal transmission function may also be one of the reasons. Even individual physical differences, intestinal flora colonization types, and the dietary structure of breastfeeders may be potential factors. This depends on subsequent further research including rectal manometry, colon transit time measurement, intestinal flora culture identification, etc.[6–8]. Since FRI does not belong to any kind of FGIDs, and the infant itself does not have any health problems, it is not ruled out as a normal physiological state.
Most infants have no obvious clinical discomfort symptoms. About 9.1% of the babies have related symptoms such as vomiting, abdominal distension, and laborious defecation, but they are mild. Although there was no significant health impact on babies during follow-up, most guardians develop significant anxiety and therefore increase outpatient visits, tests, and medications. This study found that 38.7% and 87.1% of babies had undergone various tests and treatments respectively. Common tests include gastrointestinal ultrasound, abdominal X-rays, barium enema, and blood tests for food allergens. Although some children (14.8%) have positive results, such as flatulence, gastrointestinal disorders, or serum milk protein IgE values increased, but these results have no significant clinical significance for infants with simple stool retention. Among the intervention measures, 81.7% of guardians would used glycerin enema for defecation because the baby had not been able to defecate autonomously for a long time. Other treatment methods included oral probiotics, various Chinese herbal preparations, and traditional Chinese medical therapy massage, with an effective rate of 7.8%. Glycerin enema belongs to hypertonic laxative, which can lubricate bowel wall and soften stools, it is often used for one-time laxative treatment. For infants and young children, the conditional of waiting for anal stimulation before defecation may be formed, thereby affecting voluntary defecation, so long-term use should be avoided.
Based on the fact that fecal retention will not cause obvious health effects to infants, and the treatment measures for fecal retention are ineffective, and subsequent comparative analysis found that treatment does not prevent the occurrence of FC in the future, so it is questionable whether medication is needed. The author suggests that attention should be paid to alarm symptoms, such as meconium delay, abdominal distension, and nutritional status assessment when treating infants with fecal retention. Physical examination should pay attention to digital anal examination, which can simply and quickly screen anorectal deformities, congenital megacolon and other related diseases that cause abnormal defecation. Additional imaging, blood tests, and medications are not recommended without considering organic disease. Detailed medical history inquiry, physical examination, and psychological comfort to the guardian to reduce their anxiety are more important rather than alleviating symptoms.
The literature reports that the prevalence of infant FC in the first year after birth is 2.9%, and it increases to 10.1% in the second year,the prevalence is independent of gender. We calculated that the incidence of the infants with FRI developing FC at 1 year old was 16.8%, which is significantly higher than the normal population. By comparison with other infants with normal defecation, it was found that there was no significant difference in age, frequency of stool, proportion of breastfeeding and treatment, except for duration of fecal retention. The average duration of fecal retention in FC group was 3.5 ± 0.8 months, which was longer than that in normal group. There was a significant difference between the two groups. Although the relationship between fecal retention and the risk of constipation cannot be demonstrated in this study, it is clinically judged that the longer the duration of fecal retention in infants, the higher the incidence of FC at 1 year old. Therefore more attention should be paid to how to prevent the possibility of future development of FC༌rather than how to relieve the current symptoms༌for infants with fecal retention especially those whose symptoms persist for more than 3 months.
Rationalization of diet and guidance of defecation behavior are essential to prevent FC. Some scholars believe that infants can train regular bowel movements in the early months. Defecation often occur because bowel movements are accelerated after eating. Therefore it is advisable to induce infants to defecate after meals and establish conditioned radiation. Once a good defecation pattern is formed, it can be maintained for a long time, and it can effectively prevent the occurrence of FC. Cow's milk is high in casein, and calcified casein easily forms insoluble calcium soap in the intestine, leading to dry stool. In addition too little dietary fiber and water intake in the diet can also easily cause FC. Therefore reasonable adjustment of diet structure, such as promoting breastfeeding, and appropriately increasing the daily dietary fiber and water intake will help prevent FC. Although some studies have confirmed the role of bowel habits training and dietary changes in the prevention and treatment of constipation in infants and young children, some studies have reached the opposite conclusion, so more clinical evidence is needed to support it[13, 14].