Secretin is a powerful hormone and can produce powerful side-effects. For example,
“Common side effects of secretin include flushing of the face, neck, and chest immediately after a dose. Less common side effects are vomiting, diarrhea, fainting, blood clot, fever, and rapid heartbeat. Some people can have allergic reactions including hives, redness of the skin, and a life-threatening allergic reaction (anaphylaxis).”
“Gastrointestinal side effects have included nausea, abdominal pain, vomiting, mild pancreatitis, upset stomach, burning in stomach or abdomen, diarrhea, and a warm sensation in the abdomen.” “Cardiovascular side effects have included increased heart rate, faintness, hypotension, and slow heart rate (57 bpm).” “Nervous system side effects have included headache, anxiety, numbness or tingling in extremities, possible seizure, and sedation.” “General side effects have included diaphoresis, clammy skin, increased oral secretions, and a warm sensation in the face.” “Respiratory side effects have included transient low O2 saturation and transient respiratory distress.” “Dermatologic side effects have included abdominal rash.”
There are some contraindications (something which makes a particular treatment or procedure potentially inadvisable) for secretin.
For example,
Diaphoresis (excessive sweating); Hypotension (low blood pressure); O2 saturation (level of oxygen in the blood); Respiratory distress (breathing difficulties).