Differentiating between ulcerative colitis (UC) and Crohn's disease (CD) poses a challenge to the diagnostic process because of the presence of many common symptoms in both conditions. However, through retrospective analysis and comparison with results from other publications, we can identify certain differences that may contribute to facilitating and improving diagnosis.
In the scientific work by Moazzami et al. (), one of the main symptoms observed in patients with both UC and CD was abdominal pain. In our study, we found that this symptom occurred most frequently. Unfortunately, it is a highly non-specific manifestation; therefore, in the diagnosis of inflammatory bowel diseases, it is necessary to consider additional manifestations. Moreover, patients with UC experience bloody stools and diarrhea much more frequently, which aligns with the results described by the aforementioned researchers (7). These are characteristic symptoms of UC; however, it is worth mentioning that they can also occur in cases of CD. The final diagnosis should be based on the endoscopic examination and histopathological analysis of the collected tissue samples.
In our study, weight loss occurred at a similar frequency in patients with CD and UC, indicating that this difference was not statistically significant. Moazzami et al. indicated that weight loss occurs more frequently in patients with CD (8). Discrepancies in the results may arise from differences in the characteristics of the studied populations or the methods of data analysis, including the assessment of body weight at a certain time after diagnosis.
Among the patients with UC for whom hemoglobin levels were determined, low levels were observed in 31 cases, accounting for 67.4% of the analyzed group. In contrast, anemia was present in 74.1% (n = 20) of the children with CD. In a study by Turkish scientists, anemia was also documented, but only in patients with ulcerative colitis (8). Discrepancies in the results may arise from differences in the characteristics of the studied populations or the methods of data analysis, including the assessment of body weight at a certain time after diagnosis. It is worth mentioning that among patients with UC, anemia is associated with blood loss, whereas patients with CD suffer from chronic inflammation and absorption disorders that can lead to hematological problems.
Another important aspect worth considering is inflammatory markers. In the group of examined patients, C-reactive protein (CRP) was more frequently elevated in patients with Crohn's disease (74%), whereas elevated CRP was only observed in 28% of patients with ulcerative colitis. Similar observations were made in the scientific works of other researchers (,). However, CRP should not be the primary diagnostic indicator because of its high sensitivity and potential presence in various other medical conditions such as common infections. Considering this, the next parameter that should be determined to narrow the diagnostic spectrum is the calprotectin level in the stool. In our study, no statistically significant differences were found between calprotectin levels in CD and UC, probably owing to its variable concentration depending on the stage of the disease. However, certain factors predisposing patients to disease development, such as older age and female sex, were associated with higher values of this marker at the time of diagnosis. This relationship may indicate that among girls who develop symptoms of disease relatively late or the diagnosis was made long after the first manifestation, intestinal inflammation may be the most severe, consequently leading to more complications in IBD. It is worth mentioning that despite being a more expensive test and not providing a definitive diagnosis for either of the diseases studied by us, calprotectin is a more specific parameter for inflammatory bowel diseases and shows a higher correlation with them than CRP (9). Furthermore, elevated levels can occur up to 3 months before the clinical onset of the disease symptoms ().
No difference was found between ulcerative colitis and Crohn's with regard to inorganic phosphate. In a study by Korean researchers, no sex differences were observed, but a correlation between the disease stage and phosphate content in the blood was noted; during the active phase, a significant decrease in macroelement concentrations was observed compared to the remission phase (9). In our study, we did not observe a statistically significant correlation between calprotectin levels and inorganic phosphates (p = 0.09).
In inflammatory bowel diseases, vitamin D is one of the parameters subject to significant fluctuations depending on various variables, such as genetic factors, season, disease stage, or proper supplementation. Among the children for whom vitamin D levels were determined, deficiency (levels below 20 ng/ml) was found in almost half (47.2%, n = 34) and insufficient levels (< 30 ng/ml) were identified in 77.8% (n = 56) of patients. In our analysis, a positive correlation was observed between vitamin D levels and serum iron concentrations. However, no correlation was found between vitamin D levels and inflammatory markers, including calprotectin, in stool. This differs from the results of our study (,), which may result from taking into account a one-time measurement of vitamin D concentration and not its long-term observation. Seasonal variations in vitamin D levels were also observed, with lower levels in children diagnosed with the disease in spring and winter, and higher levels in summer and autumn. However, statistical significance was not achieved in this study (p = 0.26).
Another significant issue worth noting is the direct relationship between inflammatory bowel disease, vitamin D deficiency, and bone metabolism disorders. Patients with IBD have an increased risk of developing metabolic bone disorders, mainly due to chronic inflammation, nutritional deficits, vitamin deficiencies, and steroid therapy (). Impaired absorption of fat-soluble vitamins and frequent concomitant lack of appetite during the disease may lead to reduced calcium and mineral intake, which can result in nutritional deficiencies. Steroid therapy alleviates both systemic and local inflammation, which can indirectly lead to bone disorders. Although this therapy is very effective, it significantly affects bone health and development, creating a specific vicious circle (). Scientific studies have suggested a possible correlation between serum vitamin D levels and calprotectin levels in the stool of patients with IBD (10). However, in our study, we did not achieve statistical significance for this correlation (p = 0.68). A significant proportion of the patients (68.8%) did not undergo bone density testing throughout the diagnostic process or, at least, it was not documented in the medical records. Bone health seems to be frequently overlooked, despite numerous scientific studies indicating the occurrence of metabolic bone disorders in patients with inflammatory bowel diseases (13,14,,,). Even more concerning is the result of our analysis, in which more than half of the patients who underwent bone densitometry had reduced bone density. A low calcium level recorded at the time of diagnosis should increase physicians’ vigilance regarding this aspect during the entire process of treating the child. Considering that delayed bone densitometry testing in IBD patients is often associated with lower bone density values, the issue of bone metabolism in children with non-specific inflammatory bowel diseases undoubtedly requires further research. It is crucial to identify the factors affecting bone metabolism, the mechanisms leading to reduced bone density, and to find ways to avoid the negative consequences on bone health, with the most optimal treatment outcomes for IBD.