Researchers are testing rectal injections of Botox to see whether they might help patients manage fecal incontinence—so far, results are promising. If future studies confirm success, doctors could provide patients with new ways to manage this hard-to-control condition.

Leroi A-M, Queralto M, Zerbib F, et al. Intrarectal injections of botulinum toxin versus placebo for the treatment of urge faecal incontinence in adults (fi-toxin): A double-blind, multicentre, randomised, controlled phase 3 study. The Lancet Gastroenterology & Hepatology. 2024;9(2):147-158

In a randomized, double-blind, placebo-controlled study, researchers treated nearly 200 patients for fecal incontinence using Botox or a placebo. Ninety-six patients received Botox, and 95 received the placebo treatment after nine patients withdrew from the trial before receiving injections.

Leroi A-M, Queralto M, Zerbib F, et al. Intrarectal injections of botulinum toxin versus placebo for the treatment of urge faecal incontinence in adults (fi-toxin): A double-blind, multicentre, randomised, controlled phase 3 study. The Lancet Gastroenterology & Hepatology. 2024;9(2):147-158

The Botox group received a submucosal injection of 200 units of botulinum toxin type A (BoNTA) injections, while the placebo group received the same volume of saline. Data was collected blindly for six months, after which the participants were unmasked, and members of the placebo group were offered the Botox treatment, with an additional six months of safety follow-up. The study took place in France between November 25, 2015, and November 25, 2020.

Leroi A-M, Queralto M, Zerbib F, et al. Intrarectal injections of botulinum toxin versus placebo for the treatment of urge faecal incontinence in adults (fi-toxin): A double-blind, multicentre, randomised, controlled phase 3 study. The Lancet Gastroenterology & Hepatology. 2024;9(2):147-158

Botox has been used as a treatment for urge urinary incontinence for years, with “good results and few side-effects,” adding to the researchers’ confidence regarding the success of the treatment for fecal incontinence. Other kinds of rectal injections, like Solesta injections, are also used for fecal incontinence.

Leroi A-M, Queralto M, Zerbib F, et al. Intrarectal injections of botulinum toxin versus placebo for the treatment of urge faecal incontinence in adults (fi-toxin): A double-blind, multicentre, randomised, controlled phase 3 study. The Lancet Gastroenterology & Hepatology. 2024;9(2):147-158

Bryan Curtin, MD, MHSc, a board-certified gastroenterologist and Director of The Center for Neurogastroenterology and GI Motility at The Melissa L. Posner Institute for Digestive Health and Liver Disease at Mercy Medical Center in Baltimore, MD, says that he commonly uses Solesta injections to help patients with fecal incontinence. In his experience, this yields positive results.

“I always perform an anorectal manometry and a sigmoidoscopy prior to the injections to rule out structural disease and confirm that weakened anal sphincters are present,” Dr. Curtin explains. “This intervention is not as successful if the reason for the incontinence is more due to dyssynergic defecation.”

Dr. Curtin adds that he estimates that 80% or more of his patients receive about a year of relief from one treatment.

“I have several patients that come back to me for injections yearly,” Dr. Curtin says. “Fecal incontinence is a very difficult problem to completely solve, but in my experience, the injections can reduce the frequency and severity of accidents and reduce the need for antidiarrheals such as Imodium.”

Dr. Curtin has never personally treated a patient who experienced serious side effects after the treatment.

In the Botox injection study, the most frequently reported non-serious adverse event was constipation, which, depending on how you interpret it, may imply that the treatment works too well.

Louise Hateley, a physiotherapist and Director of In Stride Health Clinic in Australia, says she is optimistic about the future of fecal incontinence treatments. 

“Quality of life can be greatly impacted by fecal incontinence, so it's critical that treatment choices progress,” Hateley says. “While pelvic floor exercises and pilates are important standard physiotherapy approaches for addressing discomfort, rectal injections may present a fresh option for individuals afflicted with this illness, which is frequently difficult to treat with traditional techniques.”

Hateley emphasizes the need for more studies on the safety and effectiveness of treatment in order to care for patients in need most appropriately.

Researchers say that more studies are needed to optimize the administration of the treatment, including pinning down specific injection sites on the body and recommended doses. Future studies must also continue to evaluate risks, assess the long-term effectiveness of the treatment, and identify the best candidates.

Depending on how future studies play out, you can offer patients this treatment instead of, or along with, existing options.