Conditions like IBS (irritable bowel disease), Crohn’s Disease, and other inflammatory diseases can increase rates of malabsorption of sugar alcohols, making symptoms far worse. 
Side effects of sugar alcohol consumption are dose-dependent, meaning the more you consume, the worse the symptoms will be (and vice versa). Additionally, research shows that symptoms are worse when sugar alcohols are consumed with other carbohydrates. 
Which Sugar Alcohols Are Keto? Which Aren’t?
Erythritol is the most ketogenic-friendly sugar alcohol. It is commonly found in keto baked goods and drinks. Research suggests it does not impact blood glucose levels and causes minimal GI issues.   
Xylitol can also be consumed on a ketogenic diet. This sweetener is commonly found in chewing gum since research shows it may improve oral health and prevent tooth decay. It does have a slightly higher glycemic index than erythritol and can cause a slight increase in blood glucose levels, but is generally well-tolerated.  
Note: xylitol is toxic to dogs and should be avoided if you have a pet-friendly home.
Maltitol and sorbitol are two polyols that should be avoided on a ketogenic diet. They are partially digested, cause an increase in blood glucose levels, and can cause severe GI issues.