Intestinal methanogen overgrowth, unspecified

This code describes the presence of an excessive amount of methane-producing microorganisms in the small intestine, leading to various gastrointestinal symptoms. It represents a specific type of dysbiosis where methanogens dominate the intestinal microbiome.

Use this code when documentation explicitly states "intestinal methanogen overgrowth" without further specification of its type. This diagnosis is typically made based on breath test results indicating elevated methane levels, often in patients presenting with chronic constipation, bloating, or abdominal discomfort.

• Do not use this code if the specific type of intestinal methanogen overgrowth (e.g., hydrogen-dominant, hydrogen sulfide-dominant) is documented.
• Consider co-coding with symptom codes (e.g., R14.0 for flatulence, K59.00 for constipation) to fully capture the patient's clinical presentation.
• Ensure documentation clearly distinguishes from general small intestinal bacterial overgrowth (SIBO) if only methanogens are implicated.