Functional Abdominal Pain in Children

When it is back-to-school time, I’m sure a lot of parents are going to hear their kids say that they have "tummy aches", whether those are real or fabricated. How do  you know if it functional abdominal pain or something else? A gastroenterologist can diagnose it.


When I was a kid, if I had a rare tummy ache my teachers would send me to the bathroom. I guess they assumed that every tummy ache was a result of problems with bowel movements, I’m not sure.

Today that "tummy ache that seems to have no cause is labeled as functional abdominal pain, and it is a common disorder in children with an estimated worldwide average prevalence of 13.5%. It is more common in females than males and in kids experiencing anxiety and depressive disorders, stress, and traumatic life events. To put that percentage in perspective, in classrooms of 30 students around the world, an average of 4 of those 30 children experience functional abdominal pain. That's a lot.

To diagnose functional abdominal pain (FAP), the criteria must be fulfilled for at least 2 months before diagnosis, must be met at least 4 times per month, and include all of the following: episodic or continuous abdominal pain that does not occur solely during physiological events such as eating and menses; insufficient criteria for other functional gastrointestinal disorders including irritable bowel syndrome, functional dyspepsia, or abdominal migraine; and after appropriate evaluation, the abdominal pain cannot be fully explained by another medical condition.

The cause of FAP is unclear, but conditions such as altered gut motility (maybe my teachers were partially correct), visceral hypersensitivity, abnormal brain-gut interaction, psychosocial disturbance, changes in intestinal microbiota, and immune activation have been suggested as possible culprits. The hypersensitivity is thought to play a central role. A higher prevalence of obesity among adolescents with FAP was noted compared to their normal-weight peers.

Current treatments mostly focus on reducing pain-generating sensations. This may include identifying underlying food intolerance, or facilitating bowel movements, or include prescription SSRi’s or tricyclic antidepressants, although the efficacy of these drugs have not been proven. Anti-spasmodic medications or peppermint oil may be helpful. Cognitive behavior therapy, electrical stimulation to the external ear or gastric area, hypnotherapy, biofeedback, stress reduction, osteopathic manipulation, acupuncture, yoga, and meditation are also examples of approaches that are used.

Apparently, there is a need for parents to be taught how to manage their children's symptoms without increasing the children's anxiety. Parents of children with FAP disorders "catastrophized more about their child's pain than parents of healthy children." (R. Pas et al.) As a parent I can completely relate to the frustration and fear the parents must feel if there seems to be no cause for their child's pain. That is understandable, but then again, it is not helpful to the child. Acceptance and commitment therapy appears to be helpful.

Today FAP is a considerable burden for families and for the children themselves. The simple instructions of yesteryear of sitting on the toilet, while still valuable for many child hood gastrointestinal complaints, does not appear to be sufficient to address this burden. Thankfully, there is always hope as a study published on parents' experiences with 14 children in Norway with FAP showed that 9 of the 14 children had recovered within 3 years between the first and second parent interviews.

What about Probiotics for Functional Abdominal Pain?

Since they have efficacy in colic, probiotics seem like they should be suited to help with FAP. However, L. rhamnosus GG and L. reuteri DSM 17938 were the only probiotics found to be rigorously studied in a 2021 meta-analysis of FAP in children. GG showed no improvement with pain. DSM 17938 showed significant reduction in pain intensity from 6 trials involving 380 children, and an increase in number of days without pain from 2 trials involving 101 children.

In the double-blind, randomized, placebo-controlled trial with 101 children, children were randomly assigned to receive either DSM 17938 or placebo for 4 weeks, with further follow-up of additional 4 weeks. At the end of the 4-week probiotic intervention, both the frequency and severity of functional abdominal pain were significantly lower in the probiotic group than in the placebo group. After the 4-week follow-up, the severity of pain remained significant lower in the probiotic group.

What Probiotic Dosages Were Used for Functional Abdominal Pain in Children?

It appears that dosages of DSM 17938 used in studies were 100-200 million CFU/day.

In another double-blind, randomized, placebo-controlled trial, 60 children aged 6-16 years were randomly allocated to receive either DSM 17938 at 200 million CFU/day or identical placebo for 4 weeks followed by a 4-week follow-up period without supplementation. The probiotic-supplemented group had significantly lower functional abdominal pain intensity compared with the placebo controls.

In yet another double-blind, randomized, placebo-controlled parallel trial investigating FAP and IBS, 46 children aged 4-18 years were randomized to receive DSM 17938 at 100 million CFU/day or placebo for 12 weeks with a 4-week follow-up. Abdominal pain was less severe in the probiotics group during the fourth month of the study and there was a significant increase in the number of days without functional abdominal pain in the probiotic group.

Where to Find DSM 17938 for Functional Abdominal Pain

L. reuteri DSM 17938 is a BioGaia strain. It is marketed as L. reuteri Protectis and is found in:

  • BioGaia Protectis Baby Drops (with or without added vitamin D), 5 drops once daily contain at least 100 million CFU. Other listed ingredients are sunflower oil and MCT oil.
  • BioGaia Protectis For Gut Comfort chewable tablets for older children and adults, 1 tablet per day contains a minimum of 100 million CFU. Other listed ingredients are isomalt, xylitol, palm oil, natural lemon flavoring, and citric acid.
  • BioGaia Gastrus For GI Tract chewable tablets combined with <em> L. reuteri</em> ATCC PTA 6475, 1 tablet per day contains at least 200 million CFU
  • BioGaia Prodentis for Gums and Teeth mint lozenges combined with <em>L. reuteri</em> ATCC PTA 5289; each tablet contains a minimum of 200 million CFU; dosage is 1-2 lozenges dissolved in the mouth per day

Always check ingredients before taking any supplement!

BioGaia states that common allergens such as egg, peanuts, tree nuts, fish, shellfish and soy have not been used in the manufacturing of BioGaia products, that BioGaia Protectis drops do not contain lactose or milk protein, and that in the finished product, the gluten level is below EU limit value for gluten-free products. According to BioGaia, in BioGaia Protectis tablets neither milk protein nor lactose are detectable, and the gluten level is below EU limit value for gluten-free products.

You can find the Baby Drops and Gut Comfort chewable tablets in my Wellevate dispensary.

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Other References:

O. Jadresin et al. “Lactobacillus reuteri DSM 17938 is effective in the treatment of functional abdominal pain in children: Results of the double-blind randomized study,” Clin Nutr 39.12 (2020):3645-3652. 

M. Brekke and A. Brodwall. “Understanding parents' experiences of disease course and influencing factors: a 3-year follow-up qualitative study among parents of children with functional abdominal pain,” BMJ Open 10.8 (2020):e037288.

T. Galai et al. “Higher prevalence of obesity among children with functional abdominal pain disorders,” BMC Pediatr 20.1 (2020):193.

R. Pas et al. “Endogenous pain modulation in children with functional abdominal pain disorders,” Pain 160.8 (2019):1883-1890.

S. Rajindrajith et al. “Functional abdominal pain disorders in children,” Expert Rev Gastroenterol Hepatol 12.4 (2018):369-390.

Z. Weizman et al. “Lactobacillus reuteri DSM 17938 for the Management of Functional Abdominal Pain in Childhood: A Randomized, Double-Blind, Placebo-Controlled Trial,” J Pediatr 174 (2016):160-164el.

C. Romano et al. “Lactobacillus reuteri in children with functional abdominal pain (FAP),” J. Paediatr Child Health 50.10 (2014):E68-71.

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