Final answer:
The comma-shaped section of the large intestine in the horse's right abdomen is the cecum, which is the first part of the colon where the appendix is attached. It assists in the absorption of water and salts and leads into the colon for further processing and absorption before waste reaches the rectum for excretion.
Step-by-step explanation:
The huge, comma-shaped section of the large intestine of the horse that occupies much of the right side of the abdomen is known as the cecum. The cecum is the first part of the large intestine, acting as a sac-like structure that is located inferior to the ileocecal valve. It plays a role in the absorption of water and salts and is connected to the appendix. The cecum seamlessly blends with the colon, which further processes waste. As the waste travels through the ascending colon on the right side of the abdomen, up to the hepatic flexure where it transitions into the transverse colon, and then down the descending colon on the left, water is absorbed, and vitamins may be absorbed in the colon.
The appendix is attached to the cecum of the colon. Fecal matter, after its water has been absorbed through the colon, becomes more solid and accumulates in the rectum before being excreted. The colon includes several parts: the ascending colon, transverse colon, descending colon, and sigmoid colon.