A month ago one of our members, Ven. A. Bhikkhu, announced the release of his in-depth study of saṃvega as it’s presented in Pali texts:
On page 67 the author gives a summary of all the things that are represented in the texts as being causes for the arising of saṃvega. Putting the author’s summary into the form of a numbered list (because that’s what we Abhidhamma fans love to do 
) I see that there are in all thirty-three items, with only a few of them entailing the actual experience of suffering:
- experience of uncertainty arising on account of non-identifiable beings.
- hearing a lion’s roar.
- anticipation of a building about to collapse.
- anticipation of whip strokes.
- direct experience of whip strokes.
- receiving monastic disciplinary measures.
- observing graceless scenes (such as a harem sleeping in unbecoming ways).
- being confronted with otherwise maladaptive behavior.
- witnessing the re-establishment of psychic powers in another person.
- tactfully having one’s superiority conceit humbled, or …
- acknowledging an inferior status on one’s own account.
- generally being endowed with personal identity view and the subsequent receiving of teachings proclaiming its origin, cessation and the path leading to such.
- uncertainty arising on account of not knowing one’s future destination.
- first-hand encounters with or second-hand stories about birth.
- … old age.
- … sickness.
- … torture.
- … death.
- contemplation of sub-human realms of deprivation.
- immediate witnessing of sub-human realms of deprivation.
- seeing the general suffering of cyclic existence and its cause.
- hearing edifying stories about human model qualities and behavior.
- the ancient pilgrim site of Lumbini.
- … Bodh Gaya.
- … Sarnath.
- … Kusinagara.
- being conscientious and scrupulous.
- receiving admonishment connected to the ultimate goal.
- listening to specifically tailored discourses.
- the augmented perception of bones and body-directed mindfulness.
- compassion.
- realizing the impermanence of grand objects (such as previous Buddhas).
- seeing the coming into existence and breaking up of a light.