Mammals have a digestive system consisting of the mouth, throat, esophagus, small intestine, large intestine, rectum and anus. The process can be divided into four parts: intake, breakdown of food, absorption of nutrients, and removal of waste.
Hindgut Digestion
Hindgut digestion is seen in monogastric herbivores, meaning they have a stomach with only a single compartment. This process assists in digesting large quantities of plant carbohydrates. Many mammals, including great apes, have a hindgut consisting of the large intestine, rectum, and anal canal.
Enlarged Intestines
Since gorillas are hindgut digestors, they process their food mostly in the large intestine rather than the stomach. Their food stays in the intestines longer to complete digestion and absorb all the nutrients. Gorillas large stomach size is due to their enlarged intestines as well as the gasses released during digestion.