"Behold, Thou desirest truth in the inward parts: and in the hidden part Thou shalt make me to know wisdom. Purge me with hyssop, and I shall be clean: wash me, and I shall be whiter than snow. Make me to hear joy and gladness; that the bones which Thou hast broken may rejoice." (Psalm 51:6-8)
Walking the splanch
Who knows? By the by, the prefix "splanch-" (hard ch) refers to the internal organs, all the ones but the heart. The heart isn't part of the splanchnic group of organs. Remember this.
"When Thou with rebukes dost correct man for iniquity, Thou makest his beauty to consume away like a moth: surely every man is vanity. Selah." (Psalm 39:11)
"O God, my heart is fixed; I will sing and give praise, even with my glory." (Psalm 108:1)
When you accepted Jesus, your heart was made in concert with His. This is the anchor from which you, as a Christian--an active believer in what Jesus for you on the cross (and you alone were you the only person in existence)--live. Day in. Day out. Howsoever, until the whole of your life begins thrumming along the same wavelength as He, there may well be a few potholes, bumps, etc. that need fine tuning and working out. This is what the "purg[ing]" and the "rebuk[ing]" spoken of in the above passages are pointing to. Everyone must, must go through this process of discipline until God feels (His feelings don't lie to Him) you're ready to do more than you thought you were cut out for. Why limit yourself?
Visceral reactions
"I will bless the Lord, who hath given me counsel: my reins also instruct me in the night seasons." (Psalm 16:7, emphasis mine)
I can't say there's a corresponding correlation to all the organs (but the heart, right?) in scripture. The physical heart pumps blood and is quite important. Metaphorically speaking, our spiritual "heart" is the place where God dwells within by His Spirit and flows out to all our life. But our lungs? How 'bout our spleen (same etymology as splanch)? The only organ I know of spoken in the Old Testament is the kidney. The Hebrew word translated "reins" is kilyah (Strong's) and refers, however metaphorically, to the mind. And while the mind may not be an organ in itself (more of an abstract yet fully usable thing), the brain is. But, since we really don't have access to our brains but through our minds, the focus must be there. After being born again, that's what God goes for and it's most certainly what the devil will aim his attacks at, too.
"Let this mind be in you, which was also in Christ Jesus: Who, being in the form of God, thought it not robbery to be equal with God: But made Himself of no reputation, and took upon Him the form of a servant, and was made in the likeness of men (inside and out): And being found in fashion as a man, he humbled Himself, and became obedient unto death, even the death of the cross." (Philippians 2:5-8)
Real quick, have you ever told God you hated Him? I have. And it's only because I wasn't thinking clearly. He understood. Didn't mean I wasn't apologetic and regretful and all that. But He understands. He understands that my thinking was not in alignment with Christ's. Something wholly under my control. Something that the discipline and correction is faithful (like Him) to exact and complete.
Taking heart
"But he knoweth the way that I take: when He hath tried me, I shall come forth as gold." (Job 23:10)
Who knows? All the stuff without is temporal. Designed to fade and wither and fall apart. This is the natural order of things. The important stuff, the stuff that God wants galvanized for His work and His purpose for your life is what He's getting at. If you find yourself (Jesus, it says in Philippians, "was found...") in the middle of confusing and untoward circumstances, but you know you're a child of God--i.e. your "heart" has been remade--rest assured He will realign everything else on your insides, as well.