Ben & Jerry's Sued For Ice Cream Causing Mouth Sores

Ben & Jerry's ice cream left a not-so-sweet aftertaste in one NYC customer's mouth -- in fact, she says it gave her some nasty lesions ... which is why she's suing.

The woman says she bought a carton of B&J's Coffee, Coffee BuzzBuzzBuzz! and ended up in the hospital afterward ... due to "oral discomfort." She says she complained to the company, and according to docs, B&J's refunded her $5.50.

In the suit she says she continued to have mouth pain for several months and visited several doctors, oral surgeons and allergists attempting to get relief ... but never did. Finally, In December 2015, she says she had surgery to remove "large white tissue" from her mouth.

The woman, who's repped by attorney Sachin Gadh, believes the BuzzBuzzBuzz! was a bad bad bad hazard that caused her sores. She wants at least $500k in damages.

We contacted Ben & Jerry's, but no word back.