Abdominal symptoms are a hallmark of CF. However, their relation with morphological abnormalities of various abdominal organs is still inadequately recognized [2].
Dysfunction of CFTR in the pancreatic ducts, biliary ducts, and intestinal epithelia results in viscous acidic secretions, leading to lumen obstruction and impaired digestion [7].
Abdominal sonography has a high value for detecting abdominal pathologies non-invasively and without exposition to radiation. It is used commonly in diagnostic evaluation and can detect abnormalities of the pancreas, liver, gallbladder, spleen, and bowel. Knowledge of these manifestations is essential in the evaluation of the extent of CF as well as the determination of treatment requirements and effectiveness in these patients [8].
In our study, 50% of patients had failure to thrive (FTT) and 70% of patients were under the 5th percentile for body weight, showing that nutritional failure in patients with CF is a common presentation that needs close follow-up. Similar to our study, Kawoosa et al. detected FTT in 94% of patients in their study in children from Jammu and Kashmir [9].
In the current study, US showed that the most frequent findings were pancreatic lipomatosis in 16 patients (26.7%), heterogeneous coarse hepatic parenchyma in 14 patients (23.3%), micro-gallbladder in 12 patients (20%), both pancreatic cystosis and liver steatosis in 10 patients (16.7%), periportal fibrosis in 8 patients (13.3%), hepatomegaly in 6 patients (10%), and both cholecystolitheasis and nodularity of liver edge in 4 patients (6.7%), and the least finding was the thickened bowel walls 2 patients (3.3%). A study conducted by Tabori et al. (2017) reported that the most frequent abdominal US findings were in order pancreatic lipomatosis (88%), liver steatosis (37%), hepatomegaly (31%), BWT (23%), and coarse hepatic parenchyma (22%) with the least finding was intussusception (2%).
In this study, intussusception was not detected in any patient. Also, a study conducted by Nandi et al. reported that intussusceptions developed in 1–3% of cases of CF, which could be the result of improved management of these patients [10]. Another study by Colombo et al. agreed with our result, in which 1% of patients with CF had a history of intussusceptions and most of them were asymptomatic [11]. In contrast to our study, Fraquelli et al. in a prospective study including 70 CF patients and 45 controls who underwent abdominal US, in which 17% of patients showed intussusception, found that patients with CF had a higher frequency of bowel US abnormalities than controls [12].
US did not detect appendiceal thickening for our patients with CF. On the contrary, a study conducted in 2004 on 31 children detected enlargement of the appendiceal diameter in most of the included children, although the patients were asymptomatic, which show that the appendiceal diameter alone may not be a factor for diagnosing appendicitis in patients with CF [13].
In the present study, there was no correlation between US finding and LFTs. This was in line with Lewindon et al.’s study, which reported that LFTs are largely non-specific in CF and considered inaccurate as a marker of severity or progression of CFLD, as patients with liver cirrhosis can have normal LFTs [14].
Currently, however, best practice guidelines recommend screening for CFLD using basic laboratory markers (LFTs, platelets, and international normalized ratio) and abdominal US. Additional imaging with CT or MRI is recommended if liver lesions or biliary tract involvement is detected on US without sufficient clarity for diagnosis [15].
In our study, RAP was the most common abdominal symptom among patients as 87% of the patients complained of RAP and 77% of patients complained of abdominal distension. Similarly, a recent survey of pain in patients throughout their lives by Sermet-Gaudelus et al. detected a high incidence of untreated pain; they included 73 children, and 59% of them reported at least one episode of pain in a month, with predominant abdominal location (60%) and 15% reported school absence and one-third of the cohort stated a negative impact on their family life [16].
Moreover, a prospective study involving children and adolescents with CF with mild severity revealed that the prevalence of RAP was as low as 6%, which was hypothesized that the low incidence of RAP in their study because of using Apley’s criteria, which described RAP as at least three attacks of pain, severe enough to disturb one’s activities, over at least period of three months, with attacks persisting in the year preceding the examination, which may result in exclusion of many children from the study with less severe pain [17].
In another study by Jeffrey et al. including 46 children, a self‐report questionnaire was used to evaluate characteristics of chronic disease‐related pain, in which 46% of the sample described the pain occurring at least once per week. Most children described their pain intensity as mild and of short duration. However, a small subgroup of children stated long‐lasting and moderately intense pain [18].
In this study, the highest burden of GI symptoms was clearly associated with pancreatic lipomatosis and liver steatosis with highest score (6/7) (p = 0.048) (Table 4). A significant relationship was detected between pancreatic cystosis and pancreatic lipomatosis by US and RAP with (P-values, 0.009 and 0.048, respectively) (Fig. 3). Prominent US findings such as pancreatic cystosis, which was detected in 10 patients (16.7%), with cyst lesions measuring up to 20 mm did not significantly contribute to the burden of abdominal symptoms in these patients with a score (5/7); however, this pathology may cause symptoms later on.
DeGruchy et al. presented a single case report of a 9-year-old girl with CF presenting with radiating abdominal pain and abdominal US showed replacement of the pancreatic head region by a large echoic cystic mass and CT confirmed multiple simple macrocysts, which indicated that pancreatic cystosis might subsequently cause symptoms, for example, when further growth of cysts compresses adjacent structures [19].
In line with our study, Tabori et al. found that patients with pancreatic lipomatosis discovered by abdominal US showed a higher abdominal pain frequency, duration, and intensity than those without pancreatic lipomatosis, but they did not agree with our results on the relationship between pancreatic cystosis and RAP as they found that pancreatic cystosis, which was detected in 6% patients, with cyst lesions measuring up to 40 mm, did not contribute significantly to the burden of abdominal symptoms in these patients.
In the recent study, the least finding was the thickened bowel walls in 2 patients (3.3%), with BWT having the lowest score (3/7). In concomitant with Tabori et al. (2017), they revealed that thickened bowel walls, as detected in (23%) in their study, were not significantly correlated with an increased burden of GI symptoms. Therefore, the etiology of bowel wall thickening in CF patients is not fully understood until now. An intestinal wall inflammation, and possibly to dysbiosis, has been encountered and, in the long run, it could lead to submucosal fibrosis [2].
The current study, no relationship was found between pancreatic enzyme replacement therapy (PERT) and US findings. Moreover, a study including patients with CF of all ages attending at the Jena University Hospital CF Center did not detect a correlation between pancreatic enzyme replacement and US abnormalities [2].
PERT is thought to be required to improve weight gain, prevent malnutrition, prevent deficiency of fat-soluble vitamins and essential fatty acids, and control abdominal symptoms of steatorrhoea [20].
