Chapter 11: Diseases of the digestive system (K00–K95)

Conditions of the mouth, gut, liver, gallbladder, pancreas and appendix: reflux and ulcers, inflammatory bowel disease, irritable bowel syndrome, hernias, gallstones, hepatitis and cirrhosis.

Chapter 11 spans codes K00–K95 in the FY2027 ICD-10-CM tabular list. This guide explains 45 of its most common codes — select a code for its official description, a plain-English explanation and a note on when the code is used.

ICD-10 Chapter 11: Digestive System — illustrative image

Codes in this chapter

Code	Official description	In plain words
K02.9	Dental caries, unspecified	Dental caries (tooth decay) is damage to a tooth caused by acid-producing bacteria in plaque.
K04.7	Periapical abscess without sinus	A periapical abscess is a pocket of infection at the tip of a tooth root, usually from untreated decay, without a draining sinus.
K05.10	Chronic gingivitis, plaque induced	Chronic gingivitis is long-term inflammation of the gums caused by plaque, making them red, swollen and prone to bleeding.
K12.0	Recurrent oral aphthae	Recurrent oral aphthae are recurring mouth ulcers (canker sores) on the soft tissues inside the mouth.
K20.90	Esophagitis, unspecified without bleeding	Oesophagitis is inflammation of the gullet (oesophagus), often from acid reflux; here without bleeding.
K21.00	Gastro-esophageal reflux disease with esophagitis, without bleeding	Gastro-oesophageal reflux disease in which stomach acid has inflamed the gullet (oesophagitis), without bleeding.
K21.9	Gastro-esophageal reflux disease without esophagitis	Gastro-oesophageal reflux disease (GERD) is reflux of stomach acid into the gullet causing heartburn, without oesophagitis.
K22.70	Barrett's esophagus without dysplasia	Barrett's oesophagus is a change in the gullet lining from long-term acid reflux that raises cancer risk; here without dysplasia.
K25.9	Gastric ulcer, unspecified as acute or chronic, without hemorrhage or perforation	A gastric ulcer is an open sore in the stomach lining; this code is used when acuity and complications are not specified.
K26.9	Duodenal ulcer, unspecified as acute or chronic, without hemorrhage or perforation	A duodenal ulcer is an open sore in the first part of the small intestine, often linked to H. pylori or anti-inflammatory medicines.
K29.70	Gastritis, unspecified, without bleeding	Gastritis is inflammation of the stomach lining, causing indigestion-like pain, nausea and fullness; here without bleeding.
K30	Functional dyspepsia	Functional dyspepsia is persistent upper abdominal discomfort or fullness with no structural cause found on investigation.
K31.84	Gastroparesis	Gastroparesis is delayed emptying of the stomach without a blockage, often related to diabetes, causing fullness, nausea and vomiting.
K35.80	Unspecified acute appendicitis	Acute appendicitis is sudden inflammation of the appendix, typically causing pain that settles in the lower right abdomen.
K40.90	Unilateral inguinal hernia, without obstruction or gangrene, not specified as recurrent	A one-sided inguinal hernia: tissue pushes through a weak spot in the groin; here without obstruction or gangrene, recurrence not specified.
K42.9	Umbilical hernia without obstruction or gangrene	An umbilical hernia is a bulge at the belly button from tissue pushing through the abdominal wall, without obstruction or gangrene.
K43.9	Ventral hernia without obstruction or gangrene	A ventral hernia is a bulge through the front abdominal wall, without obstruction or gangrene.
K44.9	Diaphragmatic hernia without obstruction or gangrene	A diaphragmatic (hiatus) hernia is when part of the stomach slides up through the diaphragm into the chest, without obstruction or gangrene.
K50.90	Crohn's disease, unspecified, without complications	Crohn's disease is a long-term inflammatory bowel disease that can affect any part of the digestive tract.
K51.90	Ulcerative colitis, unspecified, without complications	Ulcerative colitis is a long-term inflammatory bowel disease limited to the colon and rectum, causing bloody diarrhoea.
K52.9	Noninfective gastroenteritis and colitis, unspecified	Noninfective gastroenteritis and colitis: inflammation of the stomach/intestines or colon not caused by infection, with diarrhoea.
K56.609	Unspecified intestinal obstruction, unspecified as to partial versus complete obstruction	An intestinal obstruction is a blockage of the bowel preventing contents from passing; whether partial or complete is not specified.
K57.30	Diverticulosis of large intestine without perforation or abscess without bleeding	Diverticulosis is the presence of small pouches in the wall of the large bowel, without inflammation, perforation or bleeding.
K57.32	Diverticulitis of large intestine without perforation or abscess without bleeding	Diverticulitis is inflammation of pouches in the large bowel wall, causing left-sided abdominal pain and fever; here without perforation or bleeding.
K58.0	Irritable bowel syndrome with diarrhea	Irritable bowel syndrome in which diarrhoea is the main bowel pattern, with recurring abdominal pain linked to bowel habit.
K58.1	Irritable bowel syndrome with constipation	Irritable bowel syndrome in which constipation is the main bowel pattern, with recurring abdominal pain.
K58.9	Irritable bowel syndrome, unspecified	Irritable bowel syndrome (IBS) is a common functional bowel disorder of pain and altered bowel habit, here without diarrhoea predominance.
K59.00	Constipation, unspecified	Constipation means infrequent, hard or difficult-to-pass stools; the type is not specified here.
K59.04	Chronic idiopathic constipation	Chronic idiopathic constipation is long-term constipation with no identifiable cause despite investigation.
K60.2	Anal fissure, unspecified	An anal fissure is a small tear in the lining of the anus causing sharp pain and sometimes bleeding when passing stool.
K62.5	Hemorrhage of anus and rectum	Bleeding from the anus or rectum, seen as blood in the stool or on paper; the cause is coded separately.
K63.5	Polyp of colon	A polyp of the colon is a growth on the inner lining of the large bowel, usually benign but some can become cancerous over time.
K64.8	Other hemorrhoids	Other specified haemorrhoids (piles): swollen veins in the anus and lower rectum not covered by the graded internal categories.
K64.9	Unspecified hemorrhoids	Haemorrhoids (piles) are swollen veins in the anus and lower rectum that can itch, bleed or prolapse.
K70.30	Alcoholic cirrhosis of liver without ascites	Alcoholic cirrhosis is advanced scarring of the liver from long-term heavy drinking; here without ascites (fluid in the abdomen).
K74.60	Unspecified cirrhosis of liver	Cirrhosis is advanced, permanent scarring of the liver that impairs its function; the cause is not specified here.
K75.81	Nonalcoholic steatohepatitis (NASH)	Nonalcoholic steatohepatitis (NASH, also called MASH) is fatty liver with inflammation and liver-cell injury in people who drink little alcohol.
K76.0	Fatty (change of) liver, not elsewhere classified	Fatty liver (steatosis) is a build-up of fat in liver cells, common with obesity and type 2 diabetes, usually without symptoms.
K80.20	Calculus of gallbladder without cholecystitis without obstruction	A gallstone in the gallbladder (cholelithiasis) without inflammation of the gallbladder and without blockage.
K80.50	Calculus of bile duct without cholangitis or cholecystitis without obstruction	A gallstone in the bile duct (choledocholithiasis) without infection or gallbladder inflammation and without blockage.
K81.9	Cholecystitis, unspecified	Cholecystitis is inflammation of the gallbladder, usually caused by a gallstone blocking its outlet.
K85.90	Acute pancreatitis without necrosis or infection, unspecified	Acute pancreatitis is sudden inflammation of the pancreas causing severe upper abdominal pain; here without tissue death or infection.
K86.1	Other chronic pancreatitis	Other chronic pancreatitis is long-term inflammation and scarring of the pancreas damaging digestion and sometimes insulin production.
K92.1	Melena	Melaena is black, tarry stool caused by digested blood from bleeding in the upper digestive tract.
K92.2	Gastrointestinal hemorrhage, unspecified	Gastrointestinal haemorrhage means bleeding somewhere in the digestive tract; the site is not specified here.

This guide explains ICD-10-CM codes in plain language for patients, students and other readers. It is educational information only — not coding, billing or medical advice. The code recorded for any real encounter is assigned from the full clinical documentation by the treating team and qualified coders, and only they can decide which code fits a specific case.

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