What side effect is most commonly associated with anticholinergics related to the gastrointestinal system?

Anticholinergics are medications that block the action of acetylcholine, a neurotransmitter involved in various bodily functions including the regulation of the gastrointestinal (GI) system. One of the most notable side effects associated with the use of anticholinergics is constipation. This occurs because these medications reduce gastrointestinal motility and secretions, leading to a slower transit time for bowel contents and ultimately resulting in harder, less frequent stools.

In terms of GI side effects, constipation is a direct result of the anticholinergic mechanism, which decreases peristalsis—the involuntary contractions that move food through the digestive tract. As the medication inhibits these contractions, it leads to an increased water absorption in the intestines, further contributing to the formation of harder stools.

Other options, while related to gastrointestinal symptoms, do not accurately reflect the common side effect linked to anticholinergics in this context. Nausea and diarrhea can occur due to various reasons but are not typically attributed to anticholinergic effects. Hepatitis, on the other hand, is a liver condition that is unrelated to the pharmacological action of anticholinergic medications.