The digestive system (Figure 17-1) consists of the mouth, pharynx, esophagus, stomach, small intestine and large intestine (the alimentary canal), and accessory organs, which include the salivary glands, liver, gallbladder, and pancreas. The purpose of the digestive system is to process food so that it may be absorbed by cells.

Figure 17-1 Main and accessory organs of the digestive system.

The mouth is where digestion begins. The tongue, which is composed of muscle, the teeth, and saliva, facilitates mastication and assists in moving food to the pharynx, where swallowing occurs and food moves to the esophagus. Peristalsis, or the squeezing movement of food toward the stomach, occurs in the esophagus. Once the food arrives in the stomach, it is churned with gastric juices and begins the movement toward the small intestine.

The pancreas, the liver, and the gallbladder all aid in the digestive process. The purpose of the pancreas is to excrete juices that aid in the digestive process. The pancreatic duct connects with the duodenum in the same area in which the bile duct from the liver and the gallbladder intersect the duodenum. The liver secretes bile to aid in the digestive process, and the gallbladder stores bile and releases it as needed. The gallbladder is attached to the liver by the cystic duct, which joins the hepatic duct. Together, they form the common bile duct, which enters into the duodenum.

The function of the liver, in addition to aiding the digestive process, is to remove poisons from the blood, produce immune agents to control infection, and remove germs and bacteria from the blood. The liver serves as a filter for the body; a person cannot live without a functioning liver.

The small intestine contains three areas: the duodenum, the jejunum, and the ileum. The small intestine completes the digestion begun in the stomach, absorbs products of digestion, and transports residue to the large intestine. The small intestine is suspended and is attached to the abdomen by a fold of peritoneum known as the mesentery. The small intestine joins the large intestine at the ileocecal valve.

The large intestine (Figure 17-2) is composed of the cecum, colon, rectum, and anal canal. The appendix is an appendage off the cecum. The purpose of the large intestine is to absorb electrolytes and store feces until the time of elimination.

Disease Conditions

Diseases of the Digestive System (520-579), Chapter 9 in the ICD-9-CM code book, is divided into the following categories:

CATEGORY	SECTION TITLES
520-529	Diseases of the Oral Cavity, Salivary Glands, and Jaws
530-538	Diseases of the Esophagus, Stomach, and Duodenum
540-543	Appendicitis
550-553	Hernia of Abdominal Cavity
555-558	Noninfectious Enteritis and Colitis
560-569	Other Diseases of Intestines and Peritoneum
570-579	Other Diseases of Digestive System

Diseases of the Digestive System (K00-K95), Chapter 11 in the ICD-10-CM code book, are divided into the following categories:

category	SECTION TITLES
K00-K14	Diseases of Oral Cavity and Salivary Glands
K20-K31	Diseases of the Esophagus, Stomach, and Duodenum
K35-K38	Diseases of Appendix
K40-K46	Hernia
K50-K52	Noninfective Enteritis and Colitis
K55-K63	Other Diseases of Intestines
K65-K68	Diseases of Peritoneum and Retroperitoneum
K70-K77	Diseases of Liver
K80-K87	Disorders of Gallbladder, Biliary Tract, and Pancreas
K90-K95	Other Diseases of the Digestive System

Diseases of the Oral Cavity, Salivary Glands, and Jaws

Many of the conditions in these categories concern the teeth and their structures, which are often treated in the outpatient setting. Some of these conditions, however, may be treated when a patient is admitted for another condition. In the exam section of the record, a healthcare provider might document whether the patient has dentures due to edentulism, which is the complete loss of teeth. The loss of teeth might affect the patient’s ability to eat and therefore their nutritional state.

Example

Patient is admitted to the hospital with severe malnutrition and dehydration. During the exam it is identified that the patient has Class I complete edentulism, 261, 276.51, 525.41, 525.10 (E43, E86.0, K08.101).

Sialolithiasis is caused by stones in the salivary glands. Patients usually present with swollen, painful glands around the neck. When the stones are obstructing the gland, an infection, which is known as sialoadenitis, can result. Surgery may be required to remove the stone.

Example

Patient with known sialolithiasis is admitted through the ER with very painful glands in the neck and fever. After CT scan to determine the location of the stones and administration of antibiotics, the patient is taken to the OR for open removal, 527.5, 26.0 (K11.5, 0CCJ0ZZ).

Mucositis is an inflammation/ulceration of the digestive tract commonly occurring in the oral cavity. It can be found in up to 40% of patients being treated with chemotherapy. The condition can range from mild to severe. In the severest cases the patient may be unable to eat due to the pain caused by ulcerations in the mouth. It can be treated with viscous lidocaine.

Example

Patient admitted for chemotherapy for pancreatic cancer and develops ulcerative mucositis due to gemcitabine, V58.11, 157.9, 528.01, E933.1, 99.25 (Z51.11, C25.9, T45.1x5A, K12.31, 3E04305).

Exercise 17-1

Assign codes to the following conditions.

1. Canker sore	_______________
2. Ulcerative stomatitis	_______________
3. Hypertrophy of the salivary gland	_______________
4. Impacted teeth	_______________

Diseases of the Esophagus, Stomach, and Duodenum

Esophageal Conditions

Esophageal varices (Figure 17-3), one of the most common causes of esophageal hemorrhage, are excluded from the code for gastrointestinal hemorrhage. The codes for esophageal hemorrhage due to esophageal varices are found in the Circulatory System chapter.

Example

Patient has esophageal varices due to cirrhosis of the liver, 571.5, 456.21 (K74.60, I85.10).

Mallory-Weiss is the name for bleeding laceration of the esophagogastric junction that usually occurs after severe vomiting. If the bleeding is severe, an EGD may be performed to control bleeding. One of the most common conditions is esophageal reflux, which is also known as gastroesophageal reflux disease (GERD). It is treated with proton pump inhibitors such as Prilosec or, in more severe cases, by Nissen fundoplication surgery.

Barrett’s esophagus is a precancerous condition that usually occurs in people with chronic GERD. The normal cells lining the esophagus change type. Symptoms may include heartburn, indigestion, difficulty swallowing solid foods, and nocturnal regurgitation.

Example

Patient with chronic GERD who is having difficulty swallowing is found to have Barrett’s esophagus, 530.85, 530.81, 787.20 (K22.70, K21.9, R13.10).

Arteriovenous malformations (AVM) may occur in the gastrointestinal tract. The terms AVM and angiodysplasia often are used interchangeably, although an angiodysplasia is a type of AVM characterized by dilated or fragile blood vessels. AVMs may be congenital or acquired. A congenital AVM is a defect that arises during fetal development. An acquired AVM is one that develops as the result of a variety of factors during one’s lifetime. Unless specified as congenital, a gastrointestinal AVM should be coded as acquired, according to Coding Clinic (1996:3Q:p9-10; 1986:Nov-Dec:p11).1,2 For indexing of gastrointestinal AVMs, see Figure 17-4.

Figure 17-4 Indexing of gastrointestinal arteriovenous malformation (AVM).

Example

Patient presents to hospital with a GI bleed. During the workup for the cause of the bleed, it is determined that the patient has an AVM of the colon, 569.85 (K55.21).

Exercise 17-2

Assign codes to the following conditions.

1. Esophageal ulcer due to ingestion of aspirin	_______________
2. Inflammation of the esophagus due to reflux	_______________
3. Mallory-Weiss tear	_______________
4. GERD	_______________

Gastrointestinal Hemorrhage

Gastrointestinal (GI) hemorrhage is a common reason for a patient to seek medical attention. The healthcare provider must determine whether the bleed is lower or upper GI in origin, so appropriate treatment can be provided. To make this determination, the provider must evaluate how the patient presents.

In lower GI bleeds (LGIB), the patient may present with the following:

Hematochezia—bright red blood in stool

In upper GI bleeds (UGIB), the patient may present with the following:

Hematemesis—vomiting of blood

If a patient presents with melena (dark blood in stool) or occult blood in the stool (this can be found only by laboratory inspection), it is unknown without further workup whether this is an upper or a lower GI bleed. Often, when a patient presents with acute anemia without a causative condition, the healthcare provider may suspect a GI bleed.

Example

Blood in feces, occult, lab finding, 792.1 (R19.5).

GI hemorrhage has many causes; the most common causes consist of gastric or intestinal ulcers, hemorrhoids, diverticulitis, and angiodysplasia of the intestine.

Example

Patient admitted with GI bleed caused by angiodysplasia of the stomach, 537.83 (K31.811).

Example

Patient is being treated for diverticulitis of the sigmoid colon with hemorrhage, 562.13 (K57.33).

Per Coding Clinic (2005:3Q:p17-18),³ if a patient presents with a GI bleed and then undergoes diagnostic testing such as esophagogastroduodenoscopy (EGD) to determine the site of the bleed, unless the physician specifies a causal relationship between the findings on this test and the bleed, the code 578.9 (K92.2) should be assigned. Codes for any other findings such as gastritis should be coded as without hemorrhage.

Ulcers of the Stomach and Small Intestine

An ulcer of the stomach or the intestine is an open sore in the lining of the stomach or intestine. An ulcer occurs when the lining is damaged. Damage to the lining may occur when production of stomach acid is increased, or it may be caused by a bacterium known as Helicobacter pylori, or H. pylori. When locating the code for a bacterium, the main term “Infection” should be referenced in the Alphabetic Index. Ulcers may be drug-induced. The Tabular List contains instructions for the use of additional E codes to identify the responsible drug (Figure 17-5).

Figure 17-5 If an ulcer is drug- or chemical-induced, assign an E code for the responsible drug or chemical.

Symptoms of gastric ulcer may include pain when eating, vomiting, and tarry bowel movements. Ulcers can be diagnosed by means of an upper GI x-ray, blood tests that look for H. pylori, stool samples, or endoscopy. Treatment for ulcers may include antacids, drugs such as proton pump inhibitors or histamine receptor blockers, which stop the stomach from making acids, or antibiotics, and finally, in the worst case scenario, gastrectomy. Some conditions that may accompany ulcers are chronic or acute blood loss anemia and gastric outlet syndrome. A gastric ulcer is a stomach ulcer. A peptic ulcer can occur in the esophagus, stomach, duodenum, jejunum, and/or ileum. If no site is specified, 533.xx (K27.-) is assigned for peptic ulcer.

Example

Patient has a peptic ulcer of the esophagus, secondary to aspirin use, 530.20, E935.3 (K22.10, T39.015A).

Example

Patient is admitted for a bleeding gastric ulcer with obstruction and perforation, 531.61 (K25.6).

Exercise 17-3

Assign codes to the following conditions.

1. Angiodysplasia with hemorrhage of the duodenum and chronic blood loss anemia	_______________
2. Acute penetrating peptic ulcer of the duodenum	_______________
3. GI bleed due to peptic ulcer	_______________
4. Bleeding esophageal varices	_______________
5. Blood in stool	_______________

Appendicitis

Appendicitis is inflammation of the appendix that is usually caused by obstruction, which, in turn, results in infection (Figure 17-6). A patient who presents with appendicitis may have some or all of the following signs and symptoms: abdominal pain (right lower quadrant, also known as McBurney’s point), vomiting, anorexia (loss of appetite), fever, constipation, and elevated white blood cell count.

If the appendix ruptures, peritonitis develops. Patients with appendicitis are usually treated with antibiotics and surgery (appendectomy). It is important to review the pathology report for documentation of abscess or perforation of appendix.

On occasion, all signs and symptoms lead the surgeon to believe that a patient has appendicitis, but the pathology report does not confirm this diagnosis. When the pathology report indicates a normal appendix, Coding Clinic (1990:2Q:p26)⁴ instructs the coder to use the symptom the patient presented with as the principal diagnosis.

Example

Patient admitted with acute appendicitis with peritoneal abscess, 540.1 (K35.3).

Example

Patient has a ruptured appendix, 540.0 (K35.2).

Hernia of Abdominal Cavity

A hernia (Figure 17-7) is a protrusion of an organ or tissue through an abnormal opening in the body. Hernias can be present at birth or may develop over time. Most commonly, a hernia is a protrusion of the intestine through a weakness in the abdominal cavity. Hernias are classified by type or site.