There's tons of info out there like:
"Because most low-carb diets strictly limit carbohydrates, a higher proportion of calories must come from fat and protein. Fat typically accounts for roughly 45 to 65 percent of calories in a low-carb diet. If your previous diet was relatively low in fat -- maybe the generally recommended 20 to 35 percent of calories -- your body probably hasn’t ever had to process a consistently high-fat diet. When your pancreas isn't producing enough fat-digesting enzymes to keep up with demand, improperly digested fat can cause diarrhea. Unless you have an underlying health problem, however, the condition is probably temporary and should be improved by consuming less fat."
www.livestrong.com/article/361048-low-carb-diet-and-diarrhea/