Pig Digestive System Diagram – Mouth to Spiral Colon

All 18 parts on the diagram

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The tract, mouth to anus 10

Mouth Food is taken in here and chewed into smaller pieces. Saliva starts to break it down.
Salivary glands They make the saliva that wets the food. The chief ones are the parotid, mandibular and sublingual glands.
Esophagus A long tube that connects the mouth to the stomach. Waves of muscle squeeze the food along it.
Stomach A pig has one simple stomach, like a person or a dog. It is not the four-part stomach of a cow or sheep.
Liver A pig's liver is divided by deep clefts into four main lobes. It makes bile.
Small intestine Most digestion happens here, and the nutrients are absorbed through its wall. It lies in close coils and has three parts: duodenum, jejunum and ileum.
Cecum The large intestine starts with this wide, blind-ended sac. The small intestine joins the gut where the cecum and the colon meet.
Spiral colon Most of a pig's colon is wound into close spiral coils. They wind first in toward the middle and then back out.
Rectum Waste is held here until it leaves the body. The colon ends in the rectum, which runs straight back through the pelvis.
Anus The opening at the end of the tract, under the tail.

Stomach, liver and pancreas 8

Esophageal region The stomach lining round the opening of the esophagus. It is like the lining of the esophagus itself and has no glands. A sharp line separates it from the soft, glandular lining.
Cardiac gland region The thin lining of the left part of the stomach. This region is large in the pig.
Fundic gland region The thickest part of the lining. Its glands have two kinds of cells and make most of the stomach's digestive juice.
Pyloric region The last region of the lining. It narrows to the pylorus, where a knob on the wall makes the opening smaller still.
Duodenum The first part of the small intestine. Bile and the juice of the pancreas are poured into it.
Gallbladder Stores and concentrates bile made in the liver until it is needed.
Bile duct It carries bile from the liver and gallbladder to the duodenum. In the pig it opens close to the pylorus.
Pancreas It lies behind the stomach. It sends its digestive juice into the duodenum through a duct, a little beyond the bile duct.

How this list was compiled: Every name checked on 2026-09-30 against Septimus Sisson, The Anatomy of the Domestic Animals (2nd ed., 1914, public domain), Digestive System of the Pig: the mouth, salivary glands and oesophagus; the simple stomach with its blind pouch and the four regions of its lining; the coiled small intestine; the cylindrical caecum; the colon in three close, double spiral coils; rectum, liver in four main lobes, gall-bladder, bile duct and pancreas, https://archive.org/details/anatomyofdomesti00siss; and against R. D. Frandson, Anatomy and Physiology of Farm Animals (1966), read through the Internet Archive's full-text search: the simple stomach of the pig and its esophageal, cardiac gland, fundic gland and pyloric gland regions, the spiral arrangement of the pig's colon, the cecum, the salivary glands, the gallbladder and the ducts into the duodenum, https://archive.org/details/anatomyphysiolog0000rdfr. What each organ does was checked against OpenStax, Biology 2e, section 34.1 Digestive Systems, https://openstax.org/books/biology-2e/pages/34-1-digestive-systems, and OpenStax, Anatomy and Physiology 2e, section 23.4 The Stomach, https://openstax.org/books/anatomy-and-physiology-2e/pages/23-4-the-stomach. Licence: own work

The drawing: Drawn for this site on 2026-09-30 from plain geometry; nothing traced. Licence: own work

How it works

This pig digestive system diagram labeled part by part shows the whole tract inside the pig, then the stomach opened. It is a plan: the organs are spread apart so each can be seen, and the small intestine is drawn far shorter than it is.

Read the full guide

The path of food

Mouth, esophagus, stomach, small intestine, cecum, spiral colon, rectum, anus. The salivary glands and the liver add their juices on the way. The pig has one simple stomach, so this swine digestive system diagram also works as a model for other simple-stomached animals.

Inside the stomach

The lining has four regions, in order from the esophagus: esophageal, cardiac gland, fundic gland and pyloric. The duodenum leaves at the pylorus. The bile duct, from the liver and gallbladder, and the duct of the pancreas both open into it.

Opening a fetal pig? The spiral colon is the tight coil on the pig's left side. It does not unwind like the small intestine.
The cecum is a dead end. Find where the small intestine meets the colon; the cecum is the blind sac at that joint.

Questions and answers

What kind of digestive system does a pig have?

A monogastric one: a single, simple stomach, as in people and dogs. Cattle and sheep are ruminants, with a stomach in four compartments.

What is the spiral colon in a pig?

Most of the pig's colon, wound into close spiral coils that form a compact mass. The colon winds in toward the middle of the coil, turns, and winds back out before it runs on to the rectum.

What are the parts of a pig's digestive system in order?

Mouth, esophagus, stomach, small intestine (duodenum, jejunum, ileum), cecum, colon, rectum and anus. The salivary glands, liver, gallbladder and pancreas are the accessory organs that empty into the tract.

Does a pig have a gallbladder?

Yes. It lies on the liver and stores bile, which reaches the duodenum through the bile duct. Of the domestic animals, only the horse has none.