Present state and future challenges in pediatric abdominal pain therapeutics research: Looking beyond the forest

Table 1 Criteria for functional gastrointestinal disorders related to pain in children

Functional dyspepsia1

Must include all of the following

Persistent or recurrent pain or discomfort centered in the upper abdomen

Pain or discomfort not relieved by defecation or associated with onset of a change in stool frequency or form

Irritable bowel syndrome1

Must include all of the following

Abdominal pain or discomfort associated with 2 or more of the following at least 25% of the time

Improved by defecation

Onset associated with a change in stool frequency

Onset associated with a change in stool form

Abdominal migraine

Must include all of the following

Paroxysmal episodes of intense, acute periumbilical pain lasting at least one hour

Intervening periods of usual health lasting at least weeks

Pain interferes with normal activity

The pain is associated with at least two of the following

Anorexia

Nausea

Vomiting

Headache

Photophobia

Pallor

Criteria must be fulfilled at least two times in the preceeding 12 mo

Childhood functional abdominal pain1

Must include all of the following

Episodic or continuous abdominal pain

Does not meet criteria for another FGID

Childhood functional abdominal pain syndrome

Must include childhood FAP and at least 25% of the time with at least one of the following

Some loss of daily function

Additional somatic complaints such as headache, limb pain, or difficulty sleeping

All require that there be no evidence of an inflammatory, anatomic, metabolic, or neoplastic process that explains the symptoms.

¹Criteria fulfilled at least once per week for at least 12 mo. FGIDs: Functional gastrointestinal disorders; FAP: Functional abdominal pain.

Table 2 Chronological list of placebo controlled drug trials for functional gastrointestinal disorders related to abdominal pain in children and adolescents, including summary of treatment, sample size, and outcome

Ref.	Treatment	Diagnosis	Sample size (enrolled/completed)	Superior to placebo for pain relief
Symon and Russell[44] (1995)	Pitotifen	Abdominal migraine	16/14	Yes
Kline et al[45] (2001)	Enteric coated peppermint oil capsules	Irritable bowel syndrome	50/42	Yes
See et al[46] (2001)	Famotidine	Abdominal pain and dyspepsia	25/25	Yes
Friesen et al[47] (2004)	Montelukast	FD with duodenal eosinophilia	40/37	Yes
Bahar et al[48] (2008)	Amitriptyline	Irritable bowel syndrome	35/33	Yes
Sadeghian et al[49] (2008)	Cyproheptadine	Functional abdominal pain	36/28	Yes
Saps et al[50] (2009)	Amitriptyline	FD, irritable bowel syndrome, and functional abdominal pain	90/83	No
Pourmoghaddas et al[51] (2014)	Mebeverine	Functional abdominal pain	115/87	No