| ATC codes | 
|---|
| A Alimentary tract and metabolism | 
| A01 Stomatological preparations | 
| A02 Drugs for acid related disorders | 
| A03 Drugs for functional gastrointestinal disorders | 
| A04 Antiemetics and antinauseants | 
| A05 Bile and liver therapy | 
| A06 Drugs for constipation | 
| A07 Antidiarrheals, intestinal anti-inflammatory/anti-infective agents | 
| A08 Antiobesity preparations, excluding diet products | 
| A09 Digestives, including enzymes | 
| A10 Drugs used in diabetes | 
| A11 Vitamins | 
| A12 Mineral supplements | 
| A13 Tonics | 
| A14 Anabolic agents for systemic use | 
| A15 Appetite stimulants | 
| A16 Other alimentary tract and metabolism products | 
|  | 
ATC code A06 Drugs for constipation is a therapeutic subgroup of the Anatomical Therapeutic Chemical Classification System, a system of alphanumeric codes developed by the WHO for the classification of drugs and other medical products. Subgroup A06 is part of the anatomical group A Alimentary tract and metabolism.
Codes for veterinary use (ATCvet codes) can be created by placing the letter Q in front of the human ATC code: for example, QA06.
National issues of the ATC classification may include additional codes not present in this list, which follows the WHO version.