Malabsorption may not have any obvious symptoms. But if you look up in a medical reference, it will say diarrhea, steatorrhea (floating, stinky, pale stools), and weight loss are the primary symptoms - unfortunately, these only usually apply if there is fat malabsorption. There are tests that can help determine whether there is malabsorption present or if malabsorption is a possibility.
Yes, there are subtypes of malabsorption. These subtypes can be due to enzyme deficiencies or other metabolic abnormalaties (such as pernicious anemia - causes a deficiency of intrinsic factor, which prevents absorption of vitamin B12) but can also be caused by combinations of medications/foods/supplements that interact (example: acid reflux medications reduce stomach acid, which decreases absorption of protein, iron, vitamin B12, calcium, and any other nutrient that requires an acidic environment for digestion & absorption).
Taking digestive enzymes with a meal can be helpful for treating some causes of malabsorption. Nutritional supplements can also help compensate for malabsorption of specific nutrients. Timing your intake of supplements may be important in the setting of drug/nutrient interactions (e.g., taking supplements at least 2 hours before or after taking the medication that interacts with the supplement). There are other specific treatments for other enzyme/metabolic deficiencies.
Also, if dysbiosis (microbial imbalance) is causing or contributing to malabsorption, then restoring proper microbial balance in the gut would be beneficial. Probiotics may not be enough - anti-yeast and/or antibacterial medications or herbs may be needed.
Inflammation in the gut may need to be treated with anti-inflammatory herbs/medications in addition to eating a low irritation diet (i.e., no fried food/spices/caffeine/citrus/wheat/dairy/other allergens specific to you, and reduce additives like preservatives, pesticide residues, MSG, nitrites, high fructose corn syrup, etc.).
Dysmotility - there are options, such as increasing fiber, taking probiotics, motility medications, herbs that promote normal gastrointestinal motility (ginger, peppermint, etc), exercises (deep breathing, etc.), dietary modification (eliminate allergens),
I hope this helps - take care,