Low or no carbohydrate diets are meant to reduce or eliminate the carbohydrate intake of a person. Carbohydrates include mainly starches & sugary foods, which includes things like wheat or even fruits & vegetables. Instead it’s suggested the person increase their intake of protein & fatty acids. This diet is essentially the opposite of the “Soluble Fiber Diet”.
The diet is well known for being somewhat of a fad in the mid 2000s, with everyone jumping on the low-carb bandwagon. A lot of those companies are now bankrupt. Dr. Atkins himself was not necessarily a pillar of health himself, as he did have a heart attack in 2002, though this was attributed to ‘coronary artery disease’. The American Heart Association suggested it was due to his diet, the Atkins camp said it was unrelated to the Atkins diet.
There are some concerns regarding low/no carb diets as far as getting proper nutrition is concerned. However, some people have found success with IBS by reducing their carb intake.