Yes, disfellowshipping or shunning incorrigible sinners is a clear and explicit teaching in the Bible.
In fact, Jesus Christ established it as a requirement for the Christian congregation. Anyone who believes otherwise simply does not know the Bible nor Christ.
Jesus said: "If he does not listen even to the congregation, let him be to you just as a man of the nations and as a tax collector" (Mt. 18:17).
Smith's Bible Dictionary:
"Excommunication, as exercised by the Christian Church, is not merely founded on the natural right, possessed by all societies, nor merely on the example of the Jewish Church and nation. It was instituted by our Lord (Matt. xviii. 15, 18), and it was practised and commanded by St. Paul (1 Tim. i. 20; 1 Cor. v. 11; Tit. iii.10).”
Barnes’ Notes say: “The meaning of this is, cease to have religious intercourse with him, ...Regard him as obstinate, self-willed, and guilty...we should disown him as a Christian brother...This is the only way of kindness. This is the only way to preserve peace and purity in the church.”
Christ’s teachings repeatedly showed that a willful incorrigible reprobate would be “cast out” from true worshipers, especially in the “last days” during his second presence. And that “his servants” would be commanded to carry out this command (Mt. 22:12,13; 25:30; 13:49-50; 24:51; etc.).
Christ Jesus even disfellowships on what many might think are trivial grounds: “So, because you are lukewarm and neither hot nor cold, I am going to vomit you out of my mouth” (Rev. 3:15-16).
Obviously, the Apostles understood that Christ commanded the expelling of obstinate sinners since Paul showed that it was done with Christ's authority: “That in the name of our Lord Jesus,...with the power of our Lord Jesus, YOU hand such a man over to Satan” (1 Co. 5:4-5).
1 Co. 5:12-13: ”For what do I have to do with judging those outside? Do YOU not judge those inside, 13 while God judges those outside? ‘Remove the wicked man from among yourselves.’”
2 Th. 3:6,14: “Now we are giving YOU orders, brothers, in the name of the Lord Jesus Christ, to withdraw from every brother walking disorderly and not according to the tradition YOU received from us...if anyone is not obedient ...stop associating with him, that he may become ashamed.” (2 Jn. 10,11; Rm. 16:17,18; Tit. 3:10-11; Num. 16:25-26).
Eerdman's Dictionary of the Bible says:
"Excommunication. The permanent or temporary exclusion of a church member from fellowship within the community. This practice, specifically mentioned in Matthew's Gospel (Mt.18:15-17) and the Corinthian correspondence (1 Cor.5:5; 2 Cor. 2:6), served 2 purposes. First, it protects the community from the harmful influence of the sinner (1 Cor.5:6-7). Second, it reminds the sinner of the sin (2 Cor.2:7) in the hope that repentance (7:9) and redemption occur...Although the term `excommunication' does not appear in Scripture, the concept is clearly present. Matthew instructs the Church to treat unrepentant members like `a Gentile and a tax collector' (Mt.18:17), and Paul wants the guilty party delivered `over to Satan' (1 Cor.5:5), i.e., delivered over to the realm of Satan, the world outside the Church. Church discipline, ending in excommunication, should only be used for serious matters such as blatant sexual sins (1 Cor.5:1), unrepentance (Mt.18:15-17), facetiousness (Tit.3:10-11), and the propagation of heresy (Rm.16:17). Sinners should be dealt with quickly and seriously for both the health of the community and the spiritual health of the offender."
The NASB Study Bible says in a footnote at 1 Cor. 5:11-13: “Calling oneself a Christian who continues to live an immoral life is reprehensible and degrading, and gives a false testimony to Christ. If the true Christian has intimate association with someone who does this, the non-Christian world may assume that the church approves such immoral, ungodly living and thus the name of Christ would be dishonored. Questions would arise concerning of the Christian’s own testimony, …judge those who are within, The church is to exercise spiritual discipline over the professing believers in the church.”
Any Christian who got involved in immoral practices would be lovingly helped to change his way (Gal 6:1; Js. 5: 19,20). If he repents “it will be forgiven him” (Jas. 5:14-16; Acts 17:30; Pro. 28:13). If they are unrepentant the true Christian congregation would keep itself "without spot from the world" by “reproving before all onlookers” “stop mixing in company” with the individual by “removing the wicked man from among ourselves" (Jas. 1:27; 1 Tim. 5:20; 1 Cor. 5:11-13).
The true Christian religion would follow Christ’s lead and God's commands and remove willful sinners from their midst. Any religion which does not follow this mandate cannot be truly Christian.
Source: This is the Best Answer to this question from Yahoo! Answers.
Also see: Disfellowshipping - Links to Information (Defend Jehovah's Witnesses)