Diseases of the Digestive System
(ICD-10-CM Chapter 11, Codes K00-K95)
Learning Objectives
2. Identify pertinent anatomy and physiology of the digestive system
3. Identify diseases of the digestive system
4. Assign the correct Z codes and procedure codes related to the digestive system
5. Identify common treatments, medications, laboratory values, and diagnostic tests
6. Explain the importance of documentation in relation to MS-DRGs for reimbursement
Abbreviations/Acronyms
AVM arteriovenous malformation
EGD esophagogastroduodenoscopy
ERCP endoscopic retrograde cholangiopancreatography
ESWL extracorporeal shock wave lithotripsy
GERD gastroesophageal reflux disease
ICD-9-CM International Classification of Diseases, 9th Revision, Clinical Modification
ICD-10-CM International Classification of Diseases, 10th Revision, Clinical Modification
ICD-10-PCS International Classification of Diseases, 10th Revision, Procedure Coding System
IV intravenous
LGIB lower gastrointestinal bleed
MS-DRG Medicare Severity diagnosis-related group
NSAID nonsteroidal antiinflammatory drug
PEG percutaneous endoscopic gastrostomy
TIPS transjugular intrahepatic portosystemic shunt
UGIB upper gastrointestinal bleed
ICD-10-CM Official Guidelines for Coding and Reporting
There are currently no official guidelines for diseases of the digestive system. Apply the General Coding Guidelines as found in Chapter 5 of this text and the Procedural Coding Guidelines as found in Chapters 6 and 7.
Anatomy and Physiology
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.
The mouth is where digestion begins. The tongue (which is composed of muscle), the teeth, and saliva, facilitate mastication and assist 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 (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 esophagus, stomach, and duodenum |
| K35-K38 | Diseases of appendix |
| K40-K46 | Hernia |
| K50-K52 | Noninfective enteritis and colitis |
| K55-K64 | 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 and Salivary Glands (K00-K14)
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.
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.
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.
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 (K20-K31)
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.
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.
Ulcers of the esophagus are often caused by drugs or medications (Figure 17-4).
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.
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 | _______________ |
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 to use an additional code for adverse effect, if applicable to identify drug (T36-T50).
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.
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.
GI hemorrhage has many causes; the most common causes consist of gastric or intestinal ulcers, hemorrhoids, diverticulitis, and angiodysplasia of the intestine.
When 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 K92.2 should be assigned. Codes for any other findings such as gastritis should be coded as without hemorrhage.
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. Dyspepsia, gastrointestinal | _______________ |
| 5. Blood in stool | _______________ |
Diseases of the Appendix (K35-K38)
Appendicitis is inflammation of the appendix that is usually caused by obstruction, which, in turn, results in infection (Figure 17-5). 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, the symptom the patient presented with should be the principal diagnosis.
Hernia (K40-K46)
A hernia (Figure 17-6) 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. Once the site of the hernia is known, then it must be determined whether it is obstructed or gangrenous. An obstructed abdominal hernia is one in which the bowel is trapped and obstructed but viable (still working); when it becomes nonviable, it can become gangrenous (deficient blood supply to trapped bowel, making it necrotic). There is a note in ICD-10-CM that if a hernia is both obstructed and gangrenous, it should be classified to a hernia with gangrene. Some codes require documentation as to whether the hernia is unilateral or bilateral. Hernia repairs require more information and are discussed in the procedure section of this chapter.
• Inguinal—common in men, intestines protrude in the inguinal canal
• Femoral—more common in women, intestine protrudes through the femoral canal at the top of the thigh
• Umbilical—most common in children, abdominal wall is weakened at the point of the umbilical cord
Noninfectious Enteritis and Colitis (K50-K52)
Crohn’s Disease
Crohn’s disease is characterized by inflammation of the GI tract, especially the small and large intestine. It is an inflammatory bowel disease that appears to run in families. It is typically diagnosed first at the age of 20 to 30. Often there is difficulty determining Crohn’s versus ulcerative colitis. Crohn’s may also be known as ileitis or enteritis. People presenting with Crohn’s may exhibit symptoms of abdominal pain and diarrhea. Depending on the severity and location of the disease, patients may be treated with drugs to control inflammation, steroids, immunosuppressive agents, biologic response modifiers, antibiotics, and medications to control diarrhea, along with fluid replacement. Almost 75% of the patients with Crohn’s require surgery at some point in their lives to remove the diseased intestine, and they often require an ostomy.
Ulcerative Colitis
Ulcerative colitis, like Crohn’s disease, is an inflammatory bowel disease. Ulcerative colitis is a disease that produces ulcers in the lining of the rectum and colon, whereas Crohn’s disease causes inflammation deep within the intestinal wall and can occur in other parts of the digestive system, including the small intestine, mouth, esophagus, and stomach.
