Prisão de ventre vs. constipação
In the context of digestive health, prisão de ventre and constipação refer to the same condition: difficulty emptying the bowels. The main differences lie in their level of formality and regional interpretation between Brazil and Portugal.
Prisão de ventre
B1This is the colloquial, everyday term used to describe constipation. It translates literally to imprisonment of the belly. It is widely understood and used in both Brazil and Portugal in informal settings to describe the physical struggle to pass stool.
Eu preciso comer ameixas porque estou com prisão de ventre.
(I need to eat plums because I have constipation.)
A prisão de ventre é muito comum durante a gravidez.
(Constipation is very common during pregnancy.)
Beber muita água é o melhor remédio para a prisão de ventre.
(Drinking a lot of water is the best medicine for constipation.)
Constipação
B2This is the technical or medical term (often constipação intestinal). In Brazil, it is the standard word for constipation in medical contexts. However, in Portugal, constipação alone usually means a common cold (respiratory), so one must specify constipação intestinal to refer to the bowel condition there.
O médico diagnosticou o paciente com constipação crônica.
(The doctor diagnosed the patient with chronic constipation.)
A constipação intestinal pode ser causada pelo estresse excessivo.
(Intestinal constipation can be caused by excessive stress.)
O uso prolongado de laxantes pode piorar a constipação.
(Prolonged use of laxatives can worsen constipation.)
Summary
Use prisão de ventre for casual conversations in any Portuguese-speaking country; it is the safest and most descriptive term. Use constipação for medical contexts, but be aware that in Portugal, you should specify constipação intestinal to avoid saying you have a cold.