The marketing for constipation drugs is loosening up.

The FDA approval in late January of Trulance, Synergy Pharmaceuticals’ new drug for chronic idiopathic constipation, set off a tête-à-tête with Linzess, the heavily promoted drug co-marketed by Allergan and Ironwood Pharmaceuticals. Linzess was approved in 2012 for the same condition, a market that was until then dominated by Takeda Pharmaceutical and Sucampo’s Amitiza, the only other prescription drug approved to treat chronic idiopathic constipation in the U.S.

Synergy, entering a hotly contested category and looking for ways to stand out against Linzess, the reigning market leader, earlier this month launched a campaign headlined by a set of animated and personified bowel movement emojis with rhyming names like “Runny Ron” and “Mr. Smooth.”

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The unbranded campaign kicked off April 6. The emojis, dubbed the Poop Troop, are meant to help people with constipation better describe and express the emotional toll of the condition.

Allergan and Ironwood, too, have adopted a lighter tone in one of their marketing initiatives for Linzess. In a partnership with the American Gastroenterological Association, the drugmaker developed an unbranded campaign, “Toilet Talk,” featuring a video in which a woman asks strangers on the Santa Monica Pier if “they want to talk about poop.”

Even in the broader gastrointestinal market, marketers are using humor. Allergan worked with comedian Ilana Becker for its recent DTC Viberzi campaign.

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And Valeant Pharmaceuticals International’s use of the Gut Guy, an animated intestine that appeared in a Super Bowl ad, to promote IBS drug Xifaxan, may have served as an inflection point for marketers to inject humor into gastrointestinal campaigns, according to Chris Palmer, president of CDM New York, which developed the spot. “He gave people the permission to look at this condition in a slightly more light-hearted way,” he said in an email.

Linzess saw U.S. sales of $625 million last year, a 37% jump compared to 2015, while Amitiza, its main competitor, reported sales of $266 million for the first nine months of Takeda’s 2016. (The Japanese drugmaker’s fiscal year runs from April to March).

While Linzess likely holds a significant foothold in CIC, Synergy executives believe that new drugs help create a bigger market. Marino Garcia, Synergy’s EVP and chief strategy officer, made the case in March at Oppenheimer’s annual healthcare conference that the entrance of new drugs to treat CIC will expand the market rather than cannibalize market share from others. In his presentation, Garcia pointed to the growing value of the prescription constipation drug market, which doubled from $642 million in 2013 to $1.5 billion in 2016, according to QuintilesIMS data.

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To that end, Linzess is unlikely to be affected by the launch of Trulance, according to Cowen analysts, writing in an investor note in January. The firm, citing a survey it conducted of investors and physicians, concluded that Linzess sales would likely increase between 10% and 30% through 2018. The analysts forecast Linzess sales will reach roughly $1.1 billion in the U.S. by 2019.

“A strong first mover advantage is not only able to fend off follow-on competitor drugs but can also benefit from the promotional efforts of the competitor drug,” the analysts wrote in the same note.

Allergan and Ironwood increased their marketing investment in Linzess last year despite its early commercial success. Ad spend for the drug jumped 8% from 2015 to 2016, with $93 million along spent last year, according to Kantar Media.

Allergan also kicked off a campaign this month, featuring talk show host Wendy Williams. Williams attended the Vital Signs of Bowel Health summit on April 12 to encourage people with constipation to discuss their treatment options.