Children with cystic fibrosis (CF) commonly experience abdominal pain. We discuss possible causes, diagnosis and management.
Abdominal pain in children with CF is often chronic pain, and can come as a result of malabsorption, despite the use of pancreatic enzyme replacement therapy. Acute abdominal pain, however, may be a sign of the following disorders; appendicitis, constipation, gastroesophageal reflux (this occurs in up to 60% of the CF population), celiac disease, inflammatory bowel disease (increased incidence in CF), intestinal pathogens, pancreatitis and biliary disease.
Distal Intestinal Obstruction Syndrome (DIOS) should be one of the first considerations in disabling abdominal pain in CF. DIOS is an obstruction of the distal part of the small intestines. DIOS is reported to occur in 15% of patients with CF per year, while pancreatitis (1%-2%), biliary tract pain (4%), and kidney stones (6%-7%) also occur with a higher incidence in the CF population. Appendicitis has an incidence rate of 1% to 2% in CF, lower than the 7% in the general population (Britton & Saeed, 2007).
The location of the abdominal pain is an important detail. Right lower quadrant pain may indicate appendicitis; left lower quadrant pain may indicate pancreatitis and epigastric (upper abdomen, below the ribs) pain could indicate gastroesophageal reflux or gastritis (including Helicobacter pylori gastritis). Pain that radiates to the shoulder may indicate pancreatic or biliary problems. Constipation or DIOS in people with CF causes diffused pain or pain anywhere in the abdomen, depending on the location of the constipated stool. Most commonly in DIOS, the pain is in the right lower quadrant and a firm regular mass may be felt (Britton & Saeed, 2007).
If fever is present with abdominal pain, there is increased likelihood of appendicitis (Bundy et al., 2007). Decreased appetite, nausea and vomiting are associated with most causes of severe abdominal pain, however, the child who complains of abdominal pain but maintains their appetite probably does not have a serious condition. Bilious vomiting can be the first sign of appendicitis if a small bowel obstruction is present, as well as with other causes of small bowel obstruction such as intussusception (which is the inversion or telescoping of one portion of intestine within another section of intestine). In the context of CF, bilious vomiting may also be a sign of DIOS.
It is important to note that children with CF frequently continue to have large, bulky stools even if they are constipated or have DIOS, however, this is usually accompanied with abdominal distention or a history of previous episodes of either constipation or DIOS. Blood in the stools increases the concern of intussusception.
Because abdominal pain in children with CF can have multiple causes, basic laboratory tests can be helpful to screen causes of the pain. Liver function tests including bilirubin can help rule out biliary or gallbladder pain. Amylase and lipase can help diagnose pancreatitis. Full blood counts and other specific blood tests, urinalysis and urine cultures can assess infectious causes of pain such as appendicitis and urinary tract infections.
Decisions about abdominal imaging are more complicated. A basic abdominal x-ray will screen for constipation and DIOS. Depending on symptoms and other findings, abdominal/pelvic ultrasound or CT scan may be performed.
There is an increased risk of DIOS in those children with CF who were born with meconium ileus, have had bowel surgery or had previous episodes of DIOS. DIOS often occurs with a change of routine that slows down bowel function or reduces fluid content in the bowel. For example, change in diet, illness, chest exacerbation and increased physical activity. Change of social situation, such as starting school or moving to a warmer climate can also contribute. These changes are usually associated with decreased fluid intake and/or inadequate amounts of enzyme supplements. The bowel contents become thicker and stickier and can result in an obstruction of the distal part of the small intestine.
Treatment of DIOS consists of rehydration combined with laxatives. Mild cases of DIOS are treated with the laxative PEG 3350 – polyethylene glycol (Movicol or Osmolax). In more severe cases, Golytely or Gastrograffin is used and can be given via a nasogastric tube or gastrostomy. These laxatives work by drawing fluid into the bowel to soften the contents of the impacted bowel. Rehydration is achieved via increasing oral and/or intravenous fluids. In most severe cases, Gastrograffin can be given as an enema. In these severe cases the child may be reviewed by a gastroenterologist and surgeon and further investigations may be requested. However, with early aggressive medical management, surgery is seldom required.
As a previous episode of DIOS is a risk factor for reoccurrence, prophylaxis is the key. Maintaining laxative therapy is generally considered, along with avoidance of dehydration, ensuring adequate fluids and sufficient salt intake and reassessment of adequate pancreatic enzyme dosage.
Unrecognised and untreated chronic abdominal pain may negatively impact on and reduce the quality of life of children with CF. If your child is complaining of abdominal pain or discomfort, please seek the advice of your CF team.
Article from RED Magazine, Edition 2, 2017.