While the number and severity of symptoms varies among individuals, repetitive regurgitation of undigested food (known as rumination) after the start of a meal is always present. In some individuals, the regurgitation is small, occurring over a long period of time following ingestion, and can be rechewed and swallowed. In others, the amount can be bilious and short lasting, and must be expelled. While some only experience symptoms following some meals, most experience episodes following any ingestion, from a single bite to a massive feast. However, some long-term patients will find a select couple of food or drink items that do not trigger a response.
Unlike typical vomiting, the regurgitation is typically described as effortless and unforced. There is seldom nausea preceding the expulsion, and the undigested food lacks the bitter taste and odour of stomach acid and bile.
Symptoms can begin to manifest at any point from the ingestion of the meal to 120 minutes thereafter. However, the more common range is between 30 seconds to 1 hour after the completion of a meal. Symptoms tend to cease when the ruminated contents become acidic.
Abdominal pain (38.1%), lack of fecal production or constipation (21.1%), nausea (17.0%), diarrhea (8.2%), bloating (4.1%), and dental decay (3.4%) are also described as common symptoms in day-to-day life. These symptoms are not necessarily prevalent during regurgitation episodes, and can happen at any time. Weight loss is often observed (42.2%) at an average loss of 9.6 kilograms, and is more common in cases where the disorder has gone undiagnosed for a longer period of time, though this may be expected of the nutrition deficiencies that often accompany the disorder as a consequence of its symptoms. Depression has also been linked with rumination syndrome,though its effects on the disorder are unknown.