The findings of three medical doctors who asked and answered similar questions are given below.
If the soldier who pierced Jesus’s side had also pierced the side of one of the malefactors with whom Jesus was crucified, would blood and water also have come out of the malefactor’s body?
One of the doctors quoted below, Dr. Pierre Barbet, purposely created a similar scenario on several corpses for autopsies because he had similar questions. He was able to derive blood and "water" (hydropericardium) from the heart of those corpses.
I heard a sermon years ago that makes me wonder about this secondary (?) interpretation.
Further reading shows that Dr. Barbet quotes St. Jerome (Epist. 83, ad Oceanum): “This double flow consecrates at the same time the Baptism of Water and the Baptism of blood of the martyr.”
Is there more to Jesus’s blood, however, that can be explained by not spiritualizing the blood and water?
That's a tough one. I don't know how to refrain from spiritualizing a dead person because they are seen as spirits. In the case of Christ, I don't know how we would separate the "spirit" he was known to resurrect with from a body that had the same blood and water. For those that believe Christ's blood was needed for the Holy "Spirit" to enter the world and that living "water" was brought through his resurrection, it seems fair to say that the answer to that question is spiritual, regardless of it also being physiological -that one doesn't cancel out the other.
Is there a medical or physiological explanation?
Yes, according to the medical doctors quoted below, and I think their answers are better left intact.
Is it normal for both blood and water to both flow from a body in these circumstances?
Reading further, the links provided show how the act of angling the spear in a certain direction with great force caused blood and “water” (hydropericardium) to flow from Christ’s “side,” which technically was not his side since, according to these doctors, it flowed from his heart.
Publisher: Apologetics Press
Article: "An Examination of the Medical Evidence for the Physical Death of Christ"
By: Bert Thompson, PhD; Brad Harrub, PhD
“Much speculation has centered on the exact location of the puncture wound and thus the source of the resulting blood and water. However, the Greek word (pleura) that John used clearly denotes the area of the intercoastal ribs that cover the lungs (Netter, 1994, p. 184). Given the upward angle of the spear, and the thoracic location of the wound, abdominal organs can be ruled out as having provided the blood and water. A more likely scenario would suggest that the piercing affected a lung (along with any built up fluid), the pericardial sac surrounding the heart, the right atrium of the heart itself, the pulmonary vessels, and/or the aorta. Since John did not describe the specific side of the body on which the wound was inflicted, we can only speculate about which structures might have been impaled by such a vicious act. However, the blood could have resulted from the heart, the aorta, or any of the pulmonary vessels. Water probably was provided by pleural or pericardial fluids (that surround the lungs and heart).
This article can be found at: http://apologeticspress.org/apcontent.aspx?category=13&article=145
("Piercing Christ's Side")
Publisher: Journal of American Medical Association (JAMA)
Article: "On the Physical Death of Christ"
By: William D. Edwards, MD; Wesley J. Gabel, MDiv; Floyd E. Hosmer, MS, AMI)
“The gospel of John describes the piercing of Jesus’s side and emphasizes the sudden flow of blood and water. Some authors have interpreted the water to be ascites or urine, from an abdominal midline perforation of the bladder. However, the Greek word (πλευρα, or pleura) used by John clearly denoted laterality and often implied the ribs. Therefore, it seems probable that the wound was in the thorax and well away from the abdominal midline. Although the side of the wound was not designated by John, it traditionally has been depicted on the right side. Supporting this tradition is the fact that a large flow of blood would be more likely with a perforation of the distended and thin-walled right atrium or ventricle than the thick-walled and contracted left ventricle. Although the side of the wound may never be established with certainty, the right seems more probable than the left. Some of the skepticism in accepting John’s description has arisen from the difficulty in explaining, with medical accuracy, the flow of both blood and water. Part of this difficulty has been based on the assumption that the blood appeared first, then the water. However, in the ancient Greek, the order of the words generally denoted prominence and not necessarily a time sequence. Therefore, it seems likely that John was emphasizing the prominence of blood rather than its appearance preceding the water. Therefore, the water probably represented serous plural and pericardial fluid, and would have preceded the flow of blood and been smaller in volume than the blood. Perhaps in the setting of hypovolemia and impending acute heart failure, pleural and pericardial effusions may have developed and would have added to the volume of apparent water. The blood, in contrast, may have originated from the right atrium or the right ventricle or perhaps from a hemopericardium.”
Publisher: Doubleday & Company, New York
Book: "A Doctor at Calvalry: The Passion of our Lord Jesus Christ as Described by a Surgeon"
By: Pierre Burbet, MD
From Chapter 7: "Wound in the Heart" (p. 129-147)
“I say 'wound in the heart' and not wound in the side, because this is attested by tradition, and it has been confirmed for me by experiment. The blow of the lance which was given to the right side reached the auricle of the heart, perforating the pericardium… May I be forgiven if I seem to lay down the law, but I fail to see that St. John declares that there was a miracle. He certainly seems to be astonished, but is this not the issue of water alongside the blood the cause of this? Does he not mean: there issued blood, and also water? Perhaps he knew that blood can issue from a corpse; but the water would seem extraordinary to him, as at first it would even to a doctor in our day… The blood then comes quite naturally from the heart and it could only come from there in such a quantity. But whence comes the water? In my first autopsies I noticed that the pericardium always contained a quantum of serum (hydropericardium) sufficient for one to see it flowing on the incision of the parietal layer. In some cases it was most abundant. I, therefore, took my syringe once again, but I pushed the syringe very slowly, drawing into the syringe the whole time… Then, as the needle proceeded on its way, I drew out some blood from the right auricle. I then took my knife, and, inserting it with the same precautions, I saw the serum flowing and then, as I pressed on, the blood. Finally, if one inserts the knife vigorously, a large flow of blood is seen to issue from the wound; but on its edges one can also see that a lesser amount of pericardial fluid is also flowing. The water was then pericardial fluid. And one can imagine that after an exceptionally painful death-agony, as was that of the Saviour, this hydropericardium would have been particularly abundant, so much so that St. John, who was an eye- witness, was able to see both blood and water flowing. He would have imagined that the serum was water, for it has that appearance. As there was no other water than the serous fluid, it could not have been pure water. We ourselves use the word hydropericardium, which means the water contained in the pericardium… Yes, St. John was certainly clear-sighted. What he saw was the blood from the auricle and the water from the pericardium. I also have seen them, et verum est testimonium meum.”
This book is available in its entirety at: http://nebula.wsimg.com/1606eb418228091a9d54f2ad76e4b88a?AccessKeyId=C2057F426D77725ABA68&disposition=0&alloworigin=1