What Causes Recurrent Abdominal Pain?

Patient Presentation
A 7-year-old male comes to clinic with a 3 month history of abdominal pain that occurs off and on. The pain is periumbilical, lasts several minutes and then resolves. He says it “feels like someone is twisting me.” The episodes usually occur daily and sometimes several times per day. The pain does not wake him at night, but he wants to sit down when the pain occurs.
The past medical history shows that he has a normal diet and is otherwise well.
The review of systems shows he has been having harder bowel movements for the past few months with occasional painful defecation. His bowel movements are every 2-4 days and occasionally clog the toilet. The rest of his review of symptoms is negative including urinary problems.
The pertinent physical exam shows that his growth parameters are normal. His abdominal examination shows a soft, non-tender abdomen with no organomegaly and normal bowel sounds. He has stool palpable in the left lower and upper quadrants. His rectal examination shows normal tone and soft stool in the rectal vault. The rest of his genitourinary, neurological, and orthopaedic examinations are normal.
The abdominal flat plate radiograph showed stool throughout the abdomen.
The diagnosis of constipation was made. The patient was placed on a bowel clean-out program with enemas, and then started on a maintenance program with MiraLaxTM stool softener. He was also given information on how to use a toilet sitting program and increase the fiber in his diet.

Figure 6 – 12-27-04 – AP radiograph showing the colon to be filled with stool from the cecum to the rectum.

Recurrent abdominal pain is defined as attacks of abdominal pain that recur over at least 3 months in children between 4-14 years old. Acute problems like appendicitis are rarely the cause. Many children are healthy and growing with no abnormalities on physical examination or laboratory work-up.
Laboratory and/or radiological evaluations should guided by the history and physical examination and should be used, especially if there is evidence of infection, inflammation, or anatomic abnormality suspected. Usually simple tests such as a complete blood count, erythrocyte sedimentation rate, liver tests and urinalysis are all that are needed. Radiographic evaluation usually starts with a plain abdominal radiograph but may also include fluoroscopy, ultrasound, or CT scan.
Recurrent abdominal pain usually has a more ominious etiology if the following signs are present:

  • Emesis
  • Fever
  • Awakening from sleep
  • Weight loss
  • Pain that is not periumbilical
  • Blood in stool or emesis
  • Bilious emesis
  • Abnormal laboratory tests

Functional abdominal pain is caused by motility problems. Discomfort can result from contractions that can be intense and poorly coordinated and thereby be perceived as painful, especially if there is elevated sensitivity or anxiety. Functional abdominal pain often is intermittant, colicky pain not associated with meals or bowel movements. Constipation is the exception as it is is often worse after eating and better after bowel movements. Functional abdominal pain is ‘real’ pain and is not psychosomatic.
Typical features of functional abdominal pain include periumbilical location, a crampy or colicky nature, pallor during attacks, not awakening at night, missing school or other activities, a family history of abdominal pain, a high-anxiety personality and lack of ominious signs on physical examination or history.

A normal bowel pattern is thought to be a sign of good health. Constipation generally is defined as infrequent or painful defecation. Constipation can be very disturbing to the patient and family.

Most children develop constipation after the child begins to associate pain (e.g. a hard bowel movement) with defecation. The child then begins to withhold the stools trying to decrease the defecation discomfort. As stool withholding continues, the rectum dilates and gradually accommodates with the normal defecation urge disappearing. Passing large hard stools infrequently reinforces the defecation pain. The cycle continues. If the cycling is severe enough, worsening stool retention and more abnormal defecation dynamics occurs. Chronic rectal distension results in both loss of rectal sensitivity, and loss of urge to defecate, which can lead to encopresis.

Treatment mainstays are:

  • Evacuate the colon – a clean out by enemas or oral medication
  • Stop painful defecation – by using laxatives in a maintenance regimen so patients have a soft stool daily
  • Establish regular bowel habits – through toilet sitting

A balanced diet is important. Increasing dietary fiber may also help.
Medications for constipation include osmotic laxatives, stimulant laxatives, stool softeners and lubricants. MiraLax is polyethylene glycol and is an osmotic laxative. It is usually used as a maintenance medication in a dose of 0.5 -1 gram/kg/day divided BID. The dose can be titrated to have one soft stool per day.

Learning Point
A differential diagnosis of recurrent abdominal pain includes the following:

  • Gastrointestinal
    • Constipation
    • Crohn’s disease
    • Gastroesophageal reflux
    • Food sensitivity or intolerance – lactose intolerance
    • Malrotation
    • Pancreatitis – chronic, relapsing
    • Peptic ulcer
  • Genital
    • Endometriosis
    • Inguinal hernia
    • Ovarian torsion
    • Pregnancy
    • Testicular torsion
    • Sexually transmitted infection – pelvic inflammatory disease
  • Hematologic/Oncologic
    • Sickle cell anemia
    • Tumor
  • Neurologic / Psychologic
    • Abdominal epilepsy
    • Abdominal migraine
    • Abuse
    • Psychological stress
  • Renal
    • Hydronephrosis
    • Renal stones
    • Urinary tract infection
  • Miscellaneous
    • Lead poisoning
    • Parasites
    • Hereditary angioedema

Questions for Further Discussion
1. When should a patient be referred to a gastroenterologist for recurrent abdominal pain?
2. What other options than enemas are available to clean out the constipated bowel?
3. How should functional abdominal pain be evaluated and treated?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Information prescriptions for patients can be found at Pediatric Common Questions, Quick Answers for this topic: Chronic Abdominal Pain

Illingworth RS. Common Symptoms of Disease in Children. Blackwell Scientific Publications: Oxford. 1998:117-122.

Gunn VL, Nechyba C. The Harriet Lane Handbook. 16th. Edit. Mosby Publications: St. Louis. 2002:811-812.

Woodhead JC. Pediatric Clerkship Guide. Mosby., St. Louis MO, 2003:121-130.

Borowitz S. Constipation. eMedicine.
Available from the Internet at http://www.emedicine.com/ped/topic471.htm (rev. 7/14/04, cited 12/6/04).

Donna M. D’Alessandro, MD
Associate Professor of Pediatrics, Children’s Hospital of Iowa

December 27, 2004