K57.30

Diverticulitis of large intestine without perforation or abscess without bleeding

Diverticulitis of the large intestine without perforation or abscess and without bleeding (K57.30) represents an acute inflammatory condition affecting diverticula, which are small, bulging pouches that can form in the lining of the digestive system, most commonly in the colon (large intestine). This specific ICD-10 code denotes an uncomplicated form of diverticulitis, meaning there is no evidence of a breach in the bowel wall (perforation), no localized collection of pus (abscess), and no active gastrointestinal bleeding observed at the time of diagnosis. It typically signifies the initial acute presentation of symptomatic diverticular disease when inflammation occurs within one or more diverticula. The underlying pathophysiology involves the obstruction of a diverticulum, often by inspissated fecal material or undigested food particles. This obstruction leads to increased intraluminal pressure within the pouch, causing micro-perforations or erosion of the diverticular wall, and subsequent localized inflammation and infection. While considered uncomplicated due to the absence of gross perforation, abscess, or hemorrhage, the inflammatory process can still elicit significant abdominal pain, tenderness, and systemic symptoms. This condition predominantly affects individuals over 40 years of age, with its incidence increasing significantly in older populations. Lifestyle factors such as a low-fiber diet, obesity, physical inactivity, and certain medication use (e.g., NSAIDs) are recognized contributors to the development of diverticulosis, which is a prerequisite for diverticulitis. Diagnosis is primarily clinical, supported by physical examination findings, and confirmed through imaging studies such as computed tomography (CT) scans of the abdomen and pelvis, which can accurately identify inflamed diverticula and crucially rule out the presence of complications like perforation, abscess, or fistula formation. Management for uncomplicated diverticulitis typically involves a regimen of bowel rest, often with dietary modifications ranging from clear liquids to a low-fiber diet, appropriate antibiotic therapy targeting common enteric bacteria, and pain control. Close monitoring is essential to detect any progression to a more complicated state. Following resolution of the acute episode, patients are generally counselled on lifestyle and dietary changes, particularly increasing dietary fiber intake, to help prevent recurrence.

Clinical Symptoms

Left lower quadrant abdominal pain (most common, often severe and persistent)
Tenderness on palpation of the lower abdomen
Fever (typically low-grade)
Nausea
Vomiting
Changes in bowel habits (constipation or diarrhea)
Abdominal bloating or distension
Chills

Common Causes

Obstruction of a diverticulum by a fecalith (hardened stool) or undigested food particles
Increased intraluminal pressure within the colon, leading to diverticular wall erosion
Micro-perforations in the diverticular wall, causing localized inflammation
Bacterial overgrowth within the obstructed and inflamed diverticulum
Low-fiber diet (contributes to the development of diverticulosis, which predisposes to diverticulitis)
Obesity
Lack of physical activity
Smoking
Use of certain medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs) or corticosteroids

Documentation & Coding Tips

Clearly document the specific anatomical location of the diverticulitis (e.g., sigmoid colon, descending colon) and explicitly state the absence of complications such as perforation, abscess, or bleeding.

Example: Patient is a 65-year-old male presenting with acute onset severe left lower quadrant abdominal pain, fever (101.5F), and nausea for 24 hours. Physical exam reveals marked tenderness and guarding in the left lower quadrant. Labs show leukocytosis (WBC 16.2). CT abdomen/pelvis confirms acute diverticulitis involving the sigmoid colon, specifically demonstrating inflammation and wall thickening, but unequivocally *without evidence of perforation or abscess*. No hematochezia or melena reported, confirming *no bleeding*. Patient has a known history of chronic diverticulosis, and this represents an acute exacerbation. Plan: Admit to hospital, NPO, IV fluids, IV Ciprofloxacin 400mg BID and Metronidazole 500mg TID. Consult GI for ongoing management.

Billing Focus: Documentation of 'sigmoid colon' provides anatomical specificity (K57.30 is for large intestine). Explicitly stating 'without evidence of perforation or abscess' and 'no bleeding' directly supports the K57.30 code. This level of detail prevents querying for more specific codes (e.g., K57.32, K57.31) and ensures accurate billing for this specific, uncomplicated episode.

Document associated symptoms, signs, and laboratory/imaging findings that support the diagnosis, ruling out other differential diagnoses.

Example: 68-year-old female presents to the ED with 3-day history of worsening LLQ abdominal pain, associated with chills and subjective fevers. Denies dysuria, urinary frequency, or vaginal discharge. Bowel movements have been reduced, no diarrhea. Physical exam: LLQ tenderness, no rebound. Urinalysis negative for infection. CT abdomen/pelvis ordered to rule out other causes of LLQ pain, showing significant diverticular inflammation in the descending colon, but no free air, fluid collection, or contrast extravasation. This confirms acute uncomplicated diverticulitis of the descending colon. Patient is immunocompromised due to chronic steroid use for rheumatoid arthritis.

Billing Focus: Detailing associated symptoms (chills, subjective fevers), ruling out other conditions (denies dysuria/frequency/discharge, negative UA), and specifically mentioning imaging findings ('no free air, fluid collection, or contrast extravasation') strengthens the medical necessity for the diagnostic workup and confirms the diagnosis. The anatomical site ('descending colon') further refines coding.

Relevant CPT Codes

99221 - Initial Hospital Inpatient or Observation Care
Patients with acute diverticulitis often require hospitalization for intravenous antibiotics, pain control, and bowel rest, justifying initial inpatient E/M services.
99232 - Subsequent Hospital Inpatient or Observation Care
Follow-up care for admitted patients with diverticulitis, monitoring response to treatment, and managing complications or comorbidities.
74177 - CT abdomen and pelvis with contrast
CT is the gold standard for diagnosing acute diverticulitis, identifying the extent of inflammation, and ruling out complications like perforation or abscess, which is crucial for K57.30.
45378 - Colonoscopy, flexible, diagnostic
While contraindicated during acute diverticulitis, colonoscopy is often performed weeks to months after resolution of an acute episode to screen for colon cancer or evaluate for inflammatory bowel disease, especially in older patients or those with recurrent disease.
44140 - Colectomy, partial; with anastomosis
While K57.30 is uncomplicated, recurrent episodes of diverticulitis or progression to complications not captured by K57.30 might eventually necessitate surgical intervention for symptomatic relief or prevention of future complications.