Taking a shower after eating can hurt or not. It depends mainly on the temperature of the water. Shower or bathtub baths in cold water can cause thermal shock and should be avoided. If the water is warm or warm, the bath probably will not hurt.
This is because, after meals, there is a increased concentration of blood in the digestive tract because of digestion. If the bath water is cold, the body will need to increase blood flow to the skin to keep your body temperature constant.
This increased demand for blood flow to the skin removes the blood needed to digestion, making it not enough blood for the two needs: digestion and raise the skin temperature.
Thus, the heart may become unable to pump blood at a rate sufficient to meet the demands, and as a consequence, the person may even die of hypovolemic shock, a situation in which vital organs cease to receive the minimum amount of blood necessary for their functioning.
This would be a serious consequence. In some cases, the person may feel only slight discomfort, such as indigestion that can result in vomiting, with a consequent improvement in discomfort.
The same situation applies in bathing, river or sea, with the aggravating circumstance that in these cases the person enters the water and nothing, that is, performs a physical activity. Exercise requires the body to increase blood flow to the muscles, leaving the digestion aside.
To avoid complications, it is recommended that baths after eating are quick and taken in warm or hot (not too hot) water. If it is to get into the water, avoid heavier meals with fats and proteins, giving preference to light snacks and fruit juices.